A  PRACTICAL  MANUAL 


OF 


MINERALS,  MINES,  AND  MINING. 


A  PRACTICAL  MANUAL 


OF 


MINERALS,  MINES,  AND  MINING: 

COMPRISING 

SUGGESTIONS  AS  TO  THE  LOCALITIES  AND  ASSOCIATIONS 
OF  ALL  THE  USEFUL  MINERALS, 

FULL   DESCRIPTIONS   OF   THE   MOST    EFFECTIVE    METHODS   FOR  BOTH    THE 

QUALITATIVE   AND  QUANTITATIVE   ANALYSES   OF 

EACH   OF    THESE    MINERALS, 

AND 

HINTS   UPON   THE  VARIOUS   OPERATIONS   OF   MINING,  INCLUDING 
ARCHITECTURE   AND   CONSTRUCTION. 


BY 

PROF.  H.  S.  OSBORN,  LL.D., 

AUTHOR  OF   "TUB  METALLURGY  OF   IRON   AND    STEEL." 


ILLUSTRATED  BY  ONE  HUNDRED  AND  SEVENTY-ONE  ENGRAVINGS. 


PHILADELPHIA: 

HE^RY  CAREY  BAIRD  &   CO., 

INDUSTRIAL  PUBLISHERS,  BOOKSELLERS,  AND  IMPORTERS, 
810  WALNUT  STREET. 

LONDON: 
E.    &    F.    N.    SPON, 

125    STRAND. 

1888. 


-h 


COPYRIGHT  BY 
HENRY  CAREY  BAIRD  &  CO., 

1887. 


COLLINS  PRINTING  HOUSE, 

705  Jayne  Street. 


PREFACE. 


THE  object  of  this  manual  is  to  place  before  the  practical 
mineralogist  and  miner  all  the  important  help  which  may  be 
derived  from  the  present  state  of  knowledge  as  it  bears  upon 
the  departments  of  useful  mineralogy,  mining,  and  mines.  We 
have  intended  to  make  use  of  the  best  results,  not  only  of  experi- 
ment, but  of  successful  work,  and,  therefore,  only  the  best 
methods  have  been,'  in  most  cases,  presented.  Nevertheless,  it 
frequently  happens  that  a  method  adopted  in  one  condition,  or 
under  certain  circumstanced,  must  be  modified  under  other  con- 
ditions, and  there  may  be  sound  reasons  for  adopting  another 
method  to  attain  the  same  result.  Hence,  where  it  is  difficult 
to  pronounce  upon  one  method,  we  have  given  an  alternative. 

In  chemical  analyses  and  reductions,  especially  in  the  methods 
of  detection  or  determination,  we  have  confined  ourselves  to  that 
method  which  was  simplest  in  treatment.  In  practical  and 
most  technical  work  much  depends  upon  the  manipulation— 
indeed,  more  depends  upon  the  neatness  and  the  judgment  of  the 
chemist  than  upon  his  method  or  the  process  he  has  adopted. 

This  work  is  divided  into  two  principal  parts  and  one  subor- 
dinate. The  FIRST  PART  treats  of  the  t  useful  minerals — their 
physical  properties,  geologic  positions,  local  occurrence,  and 
associations ;  their  methods  of  chemical  analysis  when  we  wish 
to  determine  their  natures  and  richness ;  their  furnace  or  dry 
assay ;  and  their  probable  present  commercial  values  and  uses ; 


VI  PREFACE. 

together  with  such  cautions  which  long  experience  has  proved 
that  the  miner  and  practical  mineralogist  should  observe  in  his 
researches.  The  SECOND  PART  describes  the  various  methods  of 
excavating  and  of  timbering.  It  includes  all  brick  and  masonry 
work  during  driving,  lining,  bracing,  and  other  operations 
included  in  general  or  special  mining  architectural  work. 

Following,  Part  II.,  the  practical  work  of  digging  and  boring 
artesian  and  other  deep  wells- is  fully  described,  with  notices  of 
the  tools  used  and  how  to  provide  for  the  accidents  and  difficul- 
ties sometimes  met  with  in  these  operations. 


OXFORD,  OHIO, 

December  15,  1887. 


CONTENTS 


PART  I. 

MINING  MINERALOGY,  AND  ECONOMIC   TREATMENT  AND  HISTORY  OF 
THE  USEFUL  MINERALS. 


MINING  MINERALOGY. 

PRELIMINARY  PRINCIPLES  AND  PREPARATIONS. 

PAGE 

Necessary  requirements  for  the  successful  study  of  raining  mineralogy  .  1 7 
Crystallization,  and  importance  of  a  knowledge  of  it  ..."  .  .  18 
Hardness  of  minerals  an  important  characteristic  in  their  determination  .  19 

Cleavage;  Fracture;  Color;   Streak         •»         .- 20 

Specific  gravity;    Explanation  of;    Great  importance  of,  in  mineralogy; 
Method  for  determining         .         .         •         •         •         •         •         •         .21 

Practical  uses  of  to  miners  and  artisans      ./.«..         .          .         .         .26 

The  blow-pipe ;  Description  of,  and  manner  of  using  it     .         .         .         .       27 

Collection  of  materials  for  blow-pipe  practice    .  *         .         .         .28 

Preparatory  practice ;  Hints  for  beginners       .  .         .       29 

For  practice  in  assaying  .         .          *         .         ;. .  .          .  30 

Directions  for  removing  the  bead      *         »         .         .         .         «         .         .32 
Magnetism  ;   Application  of,  in  determining  minerals  ;  Cupellation     .         .       33 
Muffle ;   Substitute  for     .         ,         .         .         * '       .  .  .34 

In  review         .         .         •        ...        ...       ...         ,         .  .       .       35 

Chemical  analysis  ;   Elementary  principles  of  chemistry ;  The  elements      .       36 
Combining  weights  of  elementary  bodies  ;  Table  of  atomic  weights    .         .       38 
Note,  explanatory  of  the  foregoing  table         .         .         .          .          .         .39 

The  practical  use  of  the  table  of  atomic  weights         .         .         .  .39 

The  groups  ;   Grouping  of  compounds  forming  a  convenient  classification 

for  the  student,  in  their  relation  to  the  action  of  reagents  : 
First.     Metallic  oxides  not  precipitated  from  their  solutions  by  sulphuretted 
hydrogen,  hydrosulphuret  of  ammonia,  or  alkaline  carbonates — the  alka- 
lies proper    ............       42 


Till  CONTENTS. 

PAGE 

Second.  Metallic  oxides  not  precipitated  from  their  solutions  by  sulphu- 
retted hydrogen,  but  precipitated  by  hydrosulphuret  of  ammonia  only 
under  certain  circumstances,  as  salts,  and  also  precipitated  by  alkaline 

carbonates — the  alkaline  earths 42 

Third.     Metallic  oxides  not  precipitated  by  sulphuretted    hydrogen   but 
precipitated  as  oxides  by  hydrosulphuret  of  ammonia     .          .         .         .42 

Fourth.     Metallic  oxides  not  precipitated  from  their  acid  solutions  by  sul- 
phuretted hydrogen  but  completely  precipitated  by  hydrosulphuret  of  am- 
monia as  sulphurets       .....          ...  42 

Fifth.     Metallic  oxides  completely  precipitated  from  their  solutions,  whether 
acid,  alkaline,  or  neutral,  by  sulphuretted  hydrogen,  their  sulphurets  be- 
ing insoluble  in  alkaline  hydrosulphurets  ......     42 

Sixth.  Metallic  oxides  completely  precipitated  from  their  acid  solutions  by 
sulphuretted  hydrogen  but  not  from  their  alkaline  solutions,  their  sulphu- 
rets being  soluble  in  alkaline  sulphurets  .  .  .  .  .43 

Reagents;  Water 43 

Alcohol ;    Hydrogen         .  ........       44 

Chlorine  ............       45 

Bromine  and  Iodine         .          .         .  .          .         .  .          .46 

Oxygen ;   Iron          ...........       48 

Zinc;  Tin;   Hydrochloric  acid 49 

Nitric  acid  ;    Aqua  regia  ;  Sulphuric  acid  ......       50 

Hydrosulphuric   acid    gas         .         .          .         .         .         .          .          .          .51 

Acetic  acid  ;   Oxalic  acid  ;   Succinic  acid  ;  Tartaric  acid     .          .          .          .52 

Sulphurous  acid  or  anhydride  ;   Carbonic  dioxide  ;     Molybclic  acid ;     Po- 
tassa     .............       53 

Soda;   Ammonia;   Lime-water;   Alumina;  Litharge         ....        54 

Oxide  of  copper  ;  Nitrate  of  potassium  ;  Sulphate  of  potassium  ;   Carbonate 
of  potassium  ;  Black  flux       .........       55 

Chlorate  of  potassium;  Permanganate  of  potassium  ....       56 

Sulphocyanide  of  potassium  ;  Chloride  of  sodium  ;   Sulphuret  of  sodium     .       57 
Sulphite  of  sodium  ;  Carbonate  of  sodium  ;  Borax  ;  Phosphate  of  sodium  ; 

Acetate  of  sodium ;   Succinate  of  sodium        ..         .         .          .          .          .58 

Nitro  prusside  of  sodium  ;  Chloride  of  ammonium  ;   Hydrosulphide  of  am- 
monium ;  Molybdate  of  ammonium  ;  Acetate  of  ammonium    ...       59 
Oxalate  of  ammonium ;  Neutral  succinate  of  ammonium  ;   Chloride  of  ba- 
rium ;  Nitrate  of  barium  ;  Carbonate  of  barium 60 

Chloride  of  calcium  ;   Sulphate  of  Magnesium  ;  Nitrate  of  silver         .         .       61 
Litmus  paper  ;   Red  litmus  paper ;   Salt  of  lead  paper  ;   Microcosmic  salt    .        63 
Cautions  and  suggestions  ;   Selecting  a  room  for  a  laboratory      .         .         .63 
Sand  bath  ;   Assay  furnace  ;  Construction  of,  illustrated  and  described        .       64 
Analytical  scales ;  Requirement  for         .         .         .         .          .         .         .67 

How  to  use  reagents  and  glassware  .......       68 

Caution;  The  use  of  reagents ;  Heating  glassware     .         .         .  .69 


CONTENTS.  ix 

PAGE 

Heating  flasks  and  beaker  glasses  ;  Water 70 

A  list  of  usual  chemical  apparatus     .          .         .         .          .          .         .         .71 

List  of  chemicals      .         .         .         .          .          .          .          .          .          .          .72 

Folding  filter  papers  ;  Inverted  cone  of  platinum  foil  in  a  filtering  funnel  .       73 
Filtering  apparatus,  illustrated  and  described    ......        75 

Platinum  crucibles ;  Brasque    .          .         .          .          .         .          .         .         .77 

Fuming  nitric  acid  and  its  use  ........        78 

Sodium  disulphate  and  its  use  with  powdered  assays  79 

ECONOMIC  TREATMENT  AND  HISTORY  OF  THE  USEFUL 

MINERALS. 

Treatment  of  the  important  minerals ;  Comparative  standard  of  the  hard- 
ness of  a  mineral          ..'.."      .  '      .          .  .    *  ''     ".         .         .       81 
Table  of  comparative  hardness  of  minerals        .         .1        '.         .         .       82 

GOLD. 

Occurrent  condition  and  form  in  nature ;  Native  ;   Hardness  and  specific 

gravity  ;   Color  ;  Ductility  and  malleability  ;   Composition       ...       83 
United  States  localities     .          .          .         .         .         .         .         .  84 

Mines  of  South  America  and  Mexico         .         ..>./.         .         .       86 
Total  annual  production  of  gold  in  the  United  States         .         .         .         .       87 

Geology  of  gold  and  its  associations  ;  Its  combinations  with  sulphur  .          .        88 
European  localities  where  gold  has  been  found  ;  Australian  deposits  .       89 

Gold  in  gravels  and  sands  of  rivers ;  Its  occurrence  in  rocks ;  Chemical 

action  in  gold  mines  of  North  Carolina  .         .         »  .         .90 

Gold  deposits  of  North  Carolina        .         .         .         .  .          .          .91 

Native  gold  ;   Great  variety  in  the  fineness  of    .         .         .          .         .          .        92 

Alloys  of  gold  with  silver  ;   Assay  of  California  gold  by  Parisian  chemists         93 
The  characteristics  of  the  gold  of  North  Carolina,   California,   Colorado, 
and  other  American  localities  ;  Australian  gold,  variations  of  and  classifi- 
cation of  mines  ;   Study  of  the  natural  alloys  and  accompaniments  of  gold       94 
Two  curious  facts  connected  with  gold  affinities  and  alloys  ;  Gold  extracted 
from  galena  found  in  Bucks  County,  Pa.         ......       95 

Methods  of  treating  gold  alloys ;  Refining  of  gold  in  the  United  States 

Mint;  Pettenkofer's  statement  regarding  platinum  found  in  extracted  gold       96 
Best  admixture  for  smelting  gold  with  saltpetre  ;  Best  size  of  quantity  to 
be  melted  in  one  operation    .          .          .         .          .          .          .         .          .97 

Pettenkofer's  recommendation  for  extracting  gold  and  platinum  from  the  slag       98 

Re-melting  gold  containing  osm-iridium '.         .99 

Treatment  of  gold  containing  osm-iridium  at  the  mint  in  St.  Petersburg ; 
Melting  the  dross  resulting  from  the  treatment  of  Californian  and  Aus- 
tralian gold  containing  gold,  silver,  and  osm-iridium  ;  Separation  of, 
according  to  d'Hennin  ;  Extraction  of  palladium  from  augentiferous  gold  100 


X  CONTENTS. 

PAGE 

Use  of  cast  iron  in  "parting"  gold ;  Platinum  vessels  in  parting  gold  by 
means  of  sulphuric  acid;    Platinum    vessels   at  the    mint   in    Munich; 
Treatment  of  auriferous  silver  at  the  mint  in  Munich     .          .         .          .101 

Extraction  of  gold  at  St.  Petersburg  with  cast  iron  vessels ;  The  discovery 
of  and  proving  gold  ores,  necessity  of  "an  eye  for  color"  in  exploita- 
tion for  gold  ;  The  simplest  instrument  for  the  discovery  of  gold  in  fine 
dissemination  through  sand  or  dirt          .         .          .          .          .         .          .103 

Gold  cradle  or  rocker,  illustrated  and  described  ;         .         .         .          .104 

Sluice  system  of  washing  dirt  with  mercury  ;  Description  of  the  wooden 
troughs ;   Difficulty  of  amalgamation  or  combination  of  gold  with  other 
substances     .         .         .         .         .         .         .         ...         .         .     105 

Wurz's  process  of  forming  a  hard  amalgam ;   Crookes's  process  of  forming 
a  hard  amalgam    .          .          .         .         .         .         .         -  ,      •         •         •     106 

Poorer  ores  containing  gold;  Treatment  of  poor  ores         ....     107 

Hungarian  process    .         .         .          .          .         .         .         •*'."»          .108 

Necessary  precautions  in  the  treatment  of  gold  .         ..         ,         .         .     109 

SILVER. 

Occurrent  form  or  appearance  in  nature;   Native  silver,  characteristics  of; 

Hardness,  gravity,  color,  ductility,  composition  .  .  .  .  .111 
Localities,  geology,  and  associations  ;  Kongsberg  Silver  Mine,  Norway  .  112 
Silver  mines  in  the  United  States  ;  Arsenical  iron  or  mispickel .  .  .113 
Appearance  of  the  principal  ores  of  silver;  Antimonial  silver  or  dysracite  .  114 
Bismuth  silver ;  Freieslebenite  ;  Stephanite  ;  Argentite  .  .  .  ,.115 
Ruby  silver  or  pyrargyrite ;  Separation  of  the  silver  in  the  dry  way ;  Pre- 
liminary assay  as  described  by  Makins  .  .  .  .  .  .  .116 

Mitchell's  preliminary  assay  ;   Actual  assay 117 

Assay  of  shop  sweepings  ;   Scorification  ;   Makins's  operation  in  .         .     118 

Cupellation  of  the  noble  metals 120 

Cupel  furnaces,  requirements  of;  Caution  in  working  silver  with  lead         .     121 
Wet  process  or  humid  assay  of  silver ;   Process  of  Haidlen  and  Fresenius 

for  separating  silver  from  copper  ;  Process  where  gold  is  in  association    .     122 
Caution ;   Recommendation  of  Rose,  Gay  Lussac,  and  Liebig  on  treatment 

of  silver ;  To  separate  silver  from  lead  .         .          .         .         .  1 23 

Separation  of  silver  from  cadmium  and  bismuth  ;  From  mercury        .  1 24 

Silver  from  sulphurets       .         .         .         .         .         .         .          .         .          .125 

COPPER. 

Native  copper  as  a  true  ore,  locations  of,  in  the  United  States  .         .         .125 
Copper,  characteristics  of;  Hardness  ;  Behavior  before  the  blowpipe  ;  Geo- 
logical position  ;  Usual  compounded  ores 126 

Blowpipe  and  other  detection  of  copper;  By  dry  method  .         .         .127 

Wet  method ;  Caution 128 

Copper  sulphides,  decomposition  of,  and  separation  of  sulphur  .         .         .129 
Caution 131 


CONTENTS.  Xi 
NICKEL. 

PAGE 

Nickel,  characteristics  of ;    Ductility  and  tenacity ;  Nickel  glance  (Gers- 

dorffite)       .'.        ' 132 

The  Speiss  ;   Oxides  of  nickel ;  Chloride;   Sulphides         .         '. '       .         .133 

Alloys  of  nickel;   Separation  of  constituents  in  a  nickel  ore       .         .         .  134 
Deville's  method  of  obtaining  pure  nickel;  Ores  of  nickel  found  in  the 

United  States  ;  Decline  in  the  price  of  nickel         .....  135 
Use  of  nickel  for  culinary  utensils  ;  For  crucibles  in  chemical  operations  ; 

Consumption  of  nickel  in  the  United  States 136 

IRON. 

Characteristics  of  iron ;    Malleability,   ductility,  tenacity,  etc. ;  The  chief 

ores  of  iron  ;  The  magnetic  ores  ;  Magnetite          .         .         .         .         .  137 

Distribution  and  association  of  magnetic  ores    "..        .         .         .         .        ..  138 

Hematite  or  red  hematite  (specular  ore)  ;  The  largest  source  of  iron  in  the 

United  States;  Occurrence,  characteristics,  etc.  .  .  •  'f.  •  .139 

Brown  hematite  (limonite)  ;  Distribution,  characteristics,  and  peculiarities  140 

Limonite  as  a  bog  ore  in  the  United  States;  Spathic  ore  .  .  .  .  142 

Dry  assay  of  iron  ....  .  .  ,  v.  *  .  .  .  143 

Caution  . «..'.. -i  >,.  •  •  144 

Choosing  samples  for  experiments  from  an  ore  bed    ...        ,        -.         .         .  145 

Wet  method  of  assaying  iron    .          .          .          .                   .         ....  147 

Wohler's  method  of  obtaining  corroborative  proof  and  accuracy         .         .  150 

Examination  for  phosphorus ;  In  iron  sesquioxide      ...         .          .          .  151 

Parry's  method  for  precipitating  phosphorus      .          .         .         .,         .          .  152 

Deduction  of  pure  iron  in  the  assay  .  .,.*  .  .  -  *  ,..,  .  .  154 

Cautions  .  •  ...  «  .  .,  .  .  .  .  .  .  155 

Examination  for  sulphur 156 

Caution;  Determination  of  manganese      .          .          .          .         .          .          .  158 

Spathic  ore;  Kipp's  apparatus  for  determining  carbonic  dioxide,  illustrated 

and  described        .         .         .         .         .         .         .         .         .         .         .162 

Titanic  acid  (rutile)  ;  Dark -colored  iron  sand  containing  titanic  acid ; 

Where  found,  and  treatment 164 

Volumetric  determination 166 

Preparation  of  the  reagents  and  of  the  test  iron  .  .  .  '  .  .167 

Preparation  of  the  ore  for  assay 170 

Changing  a  ferric  solution  into  a  ferrous 171 

Exhaustion  of  iron-ore  deposits  in  the  United  States  ;  Remarks  of  Major 

Powell,  Director  of  the  Geological  Survey 173 

TIN. 

Characteristics  of  pure  tin 174 

Occurrent  form  ;   Stream  tin 175 


Xll  CONTENTS. 

PAGE 

Localities  and  geology      . 176 

Greisen ;   Block  tin          .          .          .          .          .          .          .         .          .          .177 

Tinstone;  Where  found;  Wood  tin;  Analysis  of  an  ore — Dr.  F.  A. 
Genth — from  the  Temescal  tin  mines,  California ;  Mineralogical  appear- 
ance .  .  .  .  .  .  .  .  .  .  .  .  1 78 

Behavior  before  the  blow-pipe 179 

Extraction  for  detection 180 

Estimating  the  quantity  of  tin  in  any  compound         .          .          .          .          .182 

ZINC. 

Occurrent  form  ;   Hardness;  Gravity;   Color;  Ductility  .         .         .         .     183 

Melting  point ;    Impurities ;    Localities ;   Zinc  sulphide  found  in  isolated 
small   pieces         .          .         .          .          .          .          .          .          .         .          .184 

Silicate  ;  Carbonate  of  zinc  ;  Zinc  sulphide  or  blende ;  Under  the  blow- 
pipe   185 

Carbonate  of  zinc  ;   Silicate  of  zinc *        .     186 

Distilling  zinc  ;   Apparatus  illustrated  and  described  ;  Treatment  of  cala- 

mine  or  blende  in  the  large  way  by  the  English  method  .  .  .187 
Belgian  and  Silesian  processes  ;  Oxide  of  zinc  ;  Characteristics  of  .  '  .  189 
Proportion  of  metallic  zinc  in  the  oxide  of  zinc;  Pure  metallic  zinc  .  .190 
Separation  of  metallic  oxides  of  groups  five  and  six  .  .  .  .  .  191 

LEAD. 

Lead;     Properties  of;   Galena;    Galenite         .         .          .         .          .          .194 

Geological  horizons  and  occurrence  ;  Geographical  distribution  of  in  the 

United  States 195 

Working  the  ore  on  the  large  scale  .  .  .  .  .  .  .  '.196 

Dry  assay  without  iron  ;  Wet  method 197 

Composition  of  lead  sulphate    .          .         .         .         .         .         .         .          .198 

Constituents  of  the  fumes  passing  off  from  lead  ores;  "Exhausters"  of 

gaseous  fumes  ;  Experiments  with  the  Sturtevant  blower  .  .  .199 
Pattinson's  process  for  separating  silver  from  lead  .....  200 
Parkes's  process  ;  Hoffman's  remarks  on  the  use  of  Parkes's  process  in  the 

United  States 201 

Lead   characteristics          ..........     202 

Wet  assay  and  methods  of  detection         .          .  .          .         .          .     203 

To  determine  lead  quantitatively  ;  Mascazzinie's  method  of  assaying  lead 

ore 204 

MANGANESE. 

Manganese;   Characteristics  of ;   Fusing  with  a  blow-pipe  ;   Associations    .     206 
Its  uses  in  the  arts  and  manufactures         .         .         .          .          .         .         .207 

Its  importance  in  the  manufacture  of  steel ;  Its  effect  upon  building  stone     208 
Analysis  for  manganese  by  the  wet  process ;   Process  of  detecting  minute 
traces  of  manganese       .         .         .         .          .         .         .         .          .         .209 


CONTENTS.  xiil 

PLATINUM. 

PAGE 

Platinum  and  the  combinations  in  which  it  is  found  ;  Characteristics  ;  Hard- 
ness; Lustre;  Color  and  streak  .  .  .  .  .'  .  ..  .  209 

Geology  and  occurrence  ;  Where  found  in  the  United  States  in  small  quan- 
tities .  ..'..'.  .  .  .  .  .  ,  .210 

Analysis  of  California  ore ;  Wet  process  of  analysis  .         .         .         .211 

IRIDIUM. 

Its  associations  and  characteristics;  Hardness;  Lustre;  Malleability  .  214 
Table  of  a  general  view  of  the  analytical  process  of  separating  the  metals 

associated  in  the  ores  of  platinum  .  .  .  .  .  •  .  .215 

Geographical  distribution  of  iridium  ;  Its  occurrence  in  the  United  States ; 

Iridium  ore  in  gold  dust  and  the  manner  of  separating  .  .  .  :  .  21G 
John  Holland's  important  discovery  in  the  melting  of  iridium  ;  Uses  of 

iridosmine    .         .         .         .         .         .        '.          .         .          .  .217 

Iridosmine  and  iridium  ;  Relative  values  of  .  ...-.•  .  •  218 

MERCURY. 

Occurrent  forms  and  associations  ;  Hardness,  gravity,  color,  ductility,  compo- 
sition ;  Boiling  and  evaporating  points  .  .  .  .  .  .218 

Localities  ;  Geology  and  associations  ;  Rocks  affording  the  metal  and  its 
ores;  The  strata  of  the  Almaden  mines,  etc.  .  .  .  .  .219 

Chemical  characteristics ;  Dissolution  of  with  acids  ;  Combining  with  met- 
als ;  Oxides  of  .....  .  .-  .  .  -.  ,  .  220 

Ores  ;  Almaden  mines  in  Spain  and  in  California  ;  Cinnabar  ore  and  its 
chemical  affinities ;  Treatment  of  the  ore  .  .  .  .  .  .  221 

Retort  process;  Roasting  the  ore;  Rumford's  cylinder  furnace;  Hiiffner 
&  Scott's  shelf  furnace  .  .  .  :  M  .  .  .  .  .  222 

Roasting  fine  ores  with  brick  or  adobes  ;  Intermittent  furnace  used  at 
New  Almaden,  California  .  .  .  .  .-  '.  .  .  .  224 

Rumford  lime-kiln  with  its  improvements  explained  by  Saml.  B.  Christy ; 
Characteristics  of  mercurial  compounds ;  Testing  insoluble  substances 
for  mercury ;  Testing  soluble  bodies ;  Action  of  stannous  chloride ;  Of 
potash,  soda,  or  ammonia  .........  225 

Action  of  hydrochloric  acid;  Of  sulphide  of  hydrogen,  or  of  ammonium 
sulphide;  Makins's  accurate  method  for  determining  mercury  in  com- 
pounds ............  226 

ANTIMONY. 

Characteristics  and  occurrence  of ;  Hardness;  Gravity;   Associations          .     227 
Stibnite  ;  Valentite  ;   Red  antimony  or  kermesite  ;   Occurrence  of  stibnite, 
action  before  the  blowpipe  ;  Antimony  associated  with  cinnabar  in  Cali- 
fornia .  228 


XIV  CONTENTS. 

PAGE 

Stibnite  deposits  in  Utah  ;  Deposits  in  foreign  lands  ....  229 
Extraction  of  antimony  from  its  ores;  Crocus  of  antimony;  Uses  and 

estimation  of  antimony          .........     230 

Composition  of  antimony ;  To  distinguish  antimony  from  Bismuth ; 

Makins's  method  of  estimating  antimony        .         .         .         .         .         .231 

Caution  in  passing  hydrogen  sulphide  through  the  hydrochloric  solution  .  232 

BISMUTH. 

Occurrence  and  characteristics;  Hardness,  gravity,  lustre,  streak,  and 
color;  Brittleness ;  Malleability;  Crystallization  .  .  .  .  232 

Fusing  point,  and  effect  upon  melting  points  of  other  metals  ;  Burning  at  a 
hi<jh  temperature  ;  Effect  of  acids  upon ;  Expansion  on  cooling  after 
fusion ;  Detection  of  bismuth ;  Its  salts ;  Action  of  dyhydric  sulphide 
or  ammomo-hydric  sulphide ;  Action  of  the  alkalies,  potash,  soda, 
or  ammonia ;  Action  of  potassic  chromate  ;  To  distinguish  bismuth  from 
lead  .  .  . .233 

Behavior  under  the  blowpipe  ;  Occurrence  of  bismuth  in  the  United  States  ; 
Its  use  in  alloys  and  amalgams  ;  Subnitrate  as  an  enamel  in  porcelain,  etc.  234 

CHROMIUM. 

Chrome  iron  or  iron  stone;  Composition  of;  Chromite;  Hardness,  gravity, 
lustre,  streak,  color ;  Action  before  the  blowpipe  .  .  .  235 

First  notice  of  its  occurrence  in  the  commercial  way ;  Deposits  in  Mary- 
land and  Pennsylvania  ;  Decomposing  the  ore;  Deposits  of  chrome  ore 
in  North  Carolina,  Virginia,  and  California  .  .  .  .  '  ;  236 

Quantitative  analysis  of  chrome  iron  ore  .         .         .         .         .         .237 

COBALT. 

Cobalt  generally  associated  with  nickel;  Cobalt  glance,  and  smaltine ; 
Zaffre;  Preparation  of  the  metal 238 

Color,  specific  gravity,  fusibility ;  Localities  of  cobalt  minerals ;  The  only 
use  of  cobalt;    Inability  to  plate  with;    Value  of  cobalt  and  of  cobalt 
oxide ;  Detection  of  its  compounds  by  the  blowpipe       .         .     -  ,         .     239 

Separation  of  cobalt  from  nickel 240 

CORUNDUM  AND  EMERY. 

Corundum  and  Emery ;  Simply  alumina  with  various  degrees  of  associated 
iron  oxide;  Corundum  in  its  purest  crystalline  state;  Color,  hardness, 
gravity,  lustre ;  Action  under  the  blowpipe  ;  Solution  in  borax  and  salt 
of  phosphorus  ;  Color  produced  by  long  heating  with  a  cobalt  solution  ; 
Association  with  crystalline  rock  ;  Ernery  at  Chester,  Mass.  .  .  .241 


CONTENTS.  XV 

PAGE 

Corundum  in  North  Carolina,  Georgia,  and  other  States  ;  Guide  or  sign  in 
searching  for ;  Uses  of  corundum  and  emery ;  Preparation  of ;  To  test 
the  abrasive  power  of  a  corundum  sample 242 

Exports  and  imports  of  emery,  1883,  1887 243 

PUMICE  STONE. 

Deposit  of,  near  San  Francisco ;  Composition  of  pumice  stone  imported 
from  the  Lepari  Islands;  Gravity,  color;  Value  of  imports,  1883,  1887  .  243 

Rotten  stone,  Tripoli,  description  and  statistics  of ;  To  gain  a  knowledge  of 
pumice  and  of  rotten  stone 244 

INFUSORIAL  EARTH. 

Composition  of;  Analysis  of  by  J.  M.  Cabell ;  Deposits  found  in  the 
United  States ;  Uses  of  this  earth  in  the  manufacture  of  polishing  pow- 
der, sand  soap,  etc.  ..........  244 

GRINDSTONES. 

Description  of  principal  source  of  supply  ;  Stone  found  near  Grindstone 
City  and  near  Marquette ;  Statistics  of  total  imports  and  of  home  pro- 
duction »  .  > 245 

BUHR  STONES. 

Leading  localities  in  the  United  States  ;  ^Esopus  stone      ....     245 
Cocalico  found  in  Lancaster  County,  Penna. ;  Berea  Grit,  found  in  Summit 

County,  Ohio ;  Uses  of  the   American  stone  and  of  those  imported  ; 

Substitution  of  rollers  for  buhr  stones  ;   Statistics  ;  True  buhr  stone        .     246 

THE  DIAMOND. 

Diamonds  found  in  the  United  States        .         .         .         .         .         .         .246 

Association  of  minerals  generally  with  the  North  Carolina  diamonds ;  Dr. 
Genth's  description  of  the  debris ;  Hardness,  gravity,  lustre,  color,  and 
general  appearance  of  monazite  .  .  .  .  .  .  .  .247 

Composition  of  and  behavior  under  the  blowpipe  ;  Xenotine,  characteristics 
and  general  appearance  of ;  Octahedrite,  hardness,  gravity,  lustre,  color, 
streak,  and  composition  of ;  Behavior  before  the  blowpipe ;  Color  pro- 
duced by  fusion  with  an  alkali  or  alkaline  carbonate  ;  Rutile  .  .  248 

Diamonds  found  in  Georgia,  California,  Idaho,  Wisconsin,  Montana,  and 
Arizona;  Gravity;  General  appearance  when  found  .  .  .  .249 

One  of  the  best  tests  of  a  diamond;  Appearance  of  the  diamond  in  the 
rough  state  ;  Their  ability  to  scratch  glass  no  proof  of  their  distinctive 
value  as  diamonds  ;  Other  glass-scratching  stones  .....  250 

Diamonds  found  in  clay  in  the  diamond  fields  of  Africa     .         .         .         .251 


XVI  CONTENTS. 


PART    II. 

MINING  WORK  AND  ARCHITECTURE,  INCLUDING  VARIOUS  SUGGESTIONS, 
WITH  DESCRIPTION  OF  ASSOCIATED  APPARATUS  AND  MACHINERY. 

MINING  CONSTRUCTION  AND  MACHINERY. 

PAGE 

Introduction     ............     255 

Some  explanation  of  terms ;  A  gangway  or  gallery,  illustrated  and  described  ; 
German,  Austrian,  English,  and  American  names  ,  .  .  .  256 

Preliminary  work  and  considerations  ;  To  make  trial  shafts  or  excavations      257 

Employment  of  borings  by  proper  machinery  ;  Examinations  for  drainage  ; 
Protection  of  the  excavations  and  supply  of  timber  or  of  masonry ;  Ac- 
cessibility to  market  one  of  the  most  important  elements  of  successful 
mining  .  .  .  .  .  .  .  .  .  ,  '  .  .  258 

Importance  of  drainage  ;  Grade  or  descent  necessary  to  prevent  overflow  ; 
Construction  of  the  main  gallery  ........  259 

Location  and  size  of  the  galleries ;  Opening  a  gallery  from  the  side  of  a 
hill,  illustrated  and  described  ;  To  begin  the  galleries  when  opening  upon 
a  vein  or  lode  ;  Working  a  mineral  vein  upward  from  the  floor  of  a  drift 
gallery :  '  •'  '  ''•  •  •  260 

Inclination  of  galleries  running  at  right  angles  to  drifts;  Sinking  a  slope 
from  the  top  of  a  hill,  illustrated  and  described ;  When  the  gallery  is 
entirely  in  the  lode  to  be  worked  out ;  While  the  gallery  is  partly  in  the 
rock  and  partly  in  the  lode ;  Putting  the  gallery  outside  when  the  lode  is 
weak ;  Putting  the  gallery  within  the  lode  when  the  rock  is  strong ; 
When  the  rock  is  not  in  horizontal  strata 261 

Building  a  gallery  at  a  distance  from  and  parallel  to  the  pay  rock,  illus- 
trated and  described 262 

Leading  off  the  water  from  mines,  illustrated  and  described  ;  Where  expe- 
dition is  required,  illustrated  and  described  ......  263 

Vertical  distances  between  galleries  built  over  each  other;  Extracting 
water  when  the  lowest  gallery  runs  beneath  the  level  of  the  water  out- 
side;  Names  of  the  galleries;  Recommendations  to  be  observed  when 
making  oreways  into  the  shaft,  between  the  usual  lifts  ;  Economic  use  of 
pumping  machinery  ..........  264 

Shaft  method  when  entrance  upon  mineral  lodes  cannot  be  made  by  drifts  ; 
Possible  forms  of  Mining  when  rock  is  to  be  penetrated  ;  Shafts  intended 
for  entrance  of  light 265 

Proper  position  of  the  "sumpt"  or  drain  reservoir;  Advantage  of  the 
slope  over  the  perpendicular  shaft ;  Cross-section  of  shaft  framing,  illus- 
trated and  described  .  .  .  .  .  .  .  .  .  .266 


CONTENTS.  XV11 

PAGE 

Use  of  a  straight  and  vertical  shaft  for  experimental  and  permanent  pur- 
poses, illustrated  and  described ;  Shaft  when  the  ore  seam  appears  of  an 
undetermined  angle,  illustrated  and  described 267 

Slope  in  the  coal  beds,  illustrated  and  described ;  Opening  of  the  shaft  in 
rock  or  soil,  illustrated  and  described 268 

Sinking  of  side-pits  when  the  roof  is  weak,  illustrated  and  described  ;  Tim- 
bering ;  Depth  and  width  of  the  dumping-floor  .....  269 

Leading  off  the  water  from  side  walls,  illustrated  and  described  .         .270 

On  the  opening  of  mines 270 

Important  rules  to  be  observed  in  opening  or  exploring  a  mine ;  The  most 
important  changes  in  ore  veins ;  Splitting,  forking,  or  scattering  of  a 
vein;  Compression  or  pinching  of  the  vein  ......  271 

Shifts  or  faults  ;  When  a  vein  divides  into  several  branches ;  When  a  vein 
becomes  pinched  or  thin  ;  When  a  vein  or  lode  is  intersected  by  another 
and  the  continuation  of  the  one  in  progress  cannot  be  found  in  the  same 
direction  .  .  .-• 272 

Distinction  to  be  made  between  the  gangue  and  ore  in  opening  a  deposit  of 
mineral,  illustrated  and  described ;  Special  consideration  of  the  rise  or 
inclination  of  the  ore  in  opening  a  lower  foot  drift,  illustrated  and  de- 
scribed .  273 

To  locate  the  opening  of  a  deposit  when  the  mountain  is  steep  and  the 
strike  of  the  vein  is  parallel  with  the  slope  of  the  mountain  ;  When  the 
strike  of  vein  is  across  the  strike  of  the  mountain  ridge  ;  When  the 
deposit  is  greatly  inclined  or  strikes  under  a  plain  ;  When  the  deposit  is 
nearly  horizontal 274 

Opening  of  large  irregular  deposits  ;  Guidance  for  mining  when  nests  or 
kidneys  of  ore  lie  separate  from  each  other ;  Requirements  of  well-con- 
ducted, scientific,  systematic  mining ;  Advantage  of  going  to  the  lower 
parts  of  the  deposit  as  soon  as  possible  .  .  .  .  .  .275 

Requirements  of  systematic  mining  both  during  the  opening  and  the  actual 
working  of  the  mine ;  Value  of  transverse  galleries,  cross-clefts  and  fis- 
sures   276 

Final  preparations  and  working  of  mines         .         .          .          .         .          .277 

Sloping  out  the  ore  ;  Division  of  the  deposits  by  levels,  drifts,  etc. ;  When 
a  mine  is  said  to  be  exposed  ;  Establishing  a  correct  relation  between  the 
preparatory  work  and  the  extracting  of  the  ore  .  .  .  .  .277 

Judicious  treatment  of  the  exposed  ore;  To  make  an  average  between  the 
higher  and  lower,  richer  and  poorer  ores  ;  Evil  results  from  "robbing  a 
mine" 278 

Regulations  for  locating  the  work  and  employment  of  hands ;  Provisions  for 
drainage,  ventilation,  security  of  the  mines  and  lives  of  the  miners  .  279 

Veins  and  lodes  ;  How  prepared  and  mined 279 

Mining  the  ore  if  the  vein  be  not  over  twelve  feet  thick,  illustrated  and 
described  .  .279 


XV111  CONTENTS. 

PAGE 

Commencing  the  final  work  of  exhausting  the  mine         ....     280 
Mining  overhead,  or  by  ascending  steps,  illustrated  and  described      .         .281 
Method  of  working  downwards,  illustrated  and  described  ....     283 
Working  when  the  vein  has  a  selvage  or  partition  rock  ;  When  the  vein  is 
firmly  attached  on  both  sides  to  the  rock  ;  Advantages  and  disadvantages 

attendant  upon  each  method  of  mining 284 

Working  when  the   ore   is  not  uniformly  rich,  or  is  deposited  in  small 
detached  masses,  illustrated  and  described  ;  When  lodes  are  more  than 
two  or  three  fathoms  in  thickness,  illustrated  and  described    .         .         .     285 
Treatment  of  the  breast  when  it  reaches  the  wall  or  is  abandoned ;  Open- 
ing of  a  second  story  immediately  over  the  first,  illustrated  and  described     286 
Working  when  a  large  mass  of  barren  rock  is  met  in  the  deposit,  illustrated 
and  described       .         .         .         .         .         .         .         .         .         .         .287 

Preparation  and  working  of  stratified  deposits  and  beds     .         .          .         .287 

Working  of  beds  of  great  inclination ;   When  the  inclination  is  less  than 

forty  degrees  :   Long  wall  system  or  post  and  stall  workings   .         .         .     287 
Detailed  working  of  the  long  wall  system,  illustrated  and  described    .         .     288 
When  the  long  wall  method  is  used  ;  Use  of  the  post  and  stall  method  ; 

Preparatory  work  for  the  post  and  stall  method,  illustrated  and  described     289 
Taking  out  the  pillars  ;  Operation  when  the  roof  is  brittle  ;  Cutting  levels 

and  drifts  in  coal-beds,  illustrated  and  described    .....     290 

In  coal-beds  of  different  layers  and  benches  illustrated ;  In  beds  of  very 
great  thickness,  illustrated  and  described  ;   Supporting  the  roof  or  walls  ; 
Spontaneous   combustion,    generally  supposed  cause  of,    and  the  most 
effective  mode  of  prevention         .         .         ..-.•„..         .         .         .291 

Preparation  and  working  of  mineral  deposits  that  occur  in  large  masses      .     292 
Mining  large  deposits  possessing  some  degree  of  regularity  ;  Deposits  with 
little  or  no  regularity  in  form  ;  Preparing' a  deposit  to  work  from  below 
upwards,  illustrated  and  described  ;  When  the  deposit  has  been  discov- 
ered by  means  of  an  adit  or  tunnel        .......     292 

When  the  deposit  has  been  discovered  by  a  shaft ;  Arrangement  of  the 
floor  and  pillars  ;  Position  of  the  miners  when  at  work ;  Operation  when 
a  vault  becomes  too  large  or  in  danger  of  crushing  in,  or  the  ore-mass  is 
composed  of  hanging  and  lying  ore- veins ;    To  gain  masses  of  inferior 
ores  difficult  of  extraction      .........     293 

To  gain  valuable  ore  after  the  mine  has  crushed  in  ;  Rock-salt  works  con- 
taining salt  in  large  and  almost  pure  masses,  operation,  illustrated  and 
described      ............     294 

Gaining  the  salt  in  a  mine  by  dissolving  it ;  Running  of  gangways  with 
rectangular  branches  conveying  water,  illustrated  and  described ;  Rock 
blasting ;  Method  used  in  progressing  against  a  breast  in  a  gangway  of  a 
salt  mine,  illustrated  ....  .  .  .  .  .  .  .295 

Preparation  and  working  of  nests,  cores,  or  pockets 295 

Surface  or  day  working 296 


CONTENTS.  XIX 

PAGE 

Class  of  deposits  to  which  it  is  applied ;   Stripping,  quarrying,  and  huddling     296 
Open  quarrying  when  the  mass  is  loose,  illustrated  and  described;  When 
solid  rock  is  to  be  quarried ;  Obtaining  large  regular  building  and  mill 
stones  ;   Obtaining  small   irregular  pieces ;  Opening  seams  in  rocks  by 
means  of  dry  woodpins          .         .          .          .          .         .          .          .          .297 

Tunneling  to  avoid  removal  of  a  very  thick  covering  and  be  able  to  work 

during  the  winter ;  Practice  at  the  iron  mines  near  Hokendauqua ;  Bud- 

dling;   Simple  method  employed  in  steep  mountain  valleys     .         .         .     298 

Use  of  washboard  for  minerals  found  in  coarse  grains,  as  gold ;  When  the 

mineral  particles  are  very  fine ;  Where  a  sufficient  head  of  water  can  be 

obtained  and  the  soil  is  loose 299 

Assorting  the  ore  in  the  mine    .         .         ...         .         .  •       .         .300 

Transportation 300 

Classification 300 

Transportation  through  galleries  and  drifts  having  an  inclination  of  more 
than  10°  and  less  than  30°,  illustrated  and  described      ....     301 

Transportation  through  shafts,  illustrated  and  described ;  Transportation  by 
shutes,  illustrated  and  described     ........     302 

Transportation  by  windlass,  illustrated  and  described          .         .         .         .303 

When  greater  weight  is  to  be  raised  from  an  unusual  depth  ;  Tarring  the 

hemp  ropes  ;  Use  of  chains  in  mines  where  the  water  is  not  acid    .         .     304 
Use  of  buckets  in  shafts ;  To  prevent  material  from  falling  into  the  shaft ; 
Effective  machines  for  shafts  of  more  than  one  hundred  and  twenty  feet 
in  depth  ;  Horse  whim,  illustrated  and  described    .....     305 

To  equalize  the  weight  and  velocity  of  ascending  and  descending  buckets ; 
Arrangement  to  empty  the  bucket  without  tilting  it        .         .         .         .306 

To  prevent  a  loaded  car  from  jumping  the  track  ;  Principal  parts  of  a  water 
whim,  illustrated  and  described ;  The  brake  attachment,  illustrated  and 

described 307 

Another  method  with  the  water  whim,  illustrated  and  described  ;  Equaliz- 
ing the  weight  of  the  buckets        .         .         .         .         .         .         .         .308 

Proper  location  of  the  whim,  illustrated  and  described ;    Use  of  turbine 
wheels ;  Form  and  curvature  of  the  blades,  illustrated  and  described ; 
Placing  the  wheel  and  shaft,  illustrated  and  described    .         .         .         .309 

Steam  engine,  illustrated  and  described     .         .         .         .         .         .         .310 

Use  and  description  of  the  eccentric 312 

Engines  arranged  for  reversing  the  action  of  the  wheel,  illustrated  and 

described 313 

Transportation  on  steep  inclines        .         .         .         .         .         .         .         .314 

Arrangement  of  the  cars,  illustrated  and  described    .         .                  .'        .314 
Dumping  the  material  from  overhead  workings ;  Use  of  cages,  illustrated 
and  described ;  To  prevent  lateral  motion  and  falling  of  the  cage ;  Emp- 
tying and  preservation  of  vessels  .- 315 


XX  CONTENTS. 

PAGE 

Ladders  for  ingress  or  egress  of  workmen,  illustrated  and  described  ;  Plat- 
forms worked  by  machinery,  illustrated  and  described  .  .  .  .316 

Timbering  and  masonry 317 

When  the  rock  of  a  mine  is  not  perfectly  firm ;  If  the  spaces  are  to  be 

self-supporting ;  Pillars  of  native  rock  ;  Artificial  pillars        .  .317 

Conditions  to  be  considered  before  deciding  upon  timbering  or  masonry  .  318 
Mining  carpentry  .  .  .  .  »  •  .•••••».-•  •  318 
Selection,  preparation,  and  placing  of  the  timbers  »-  ,  .  .  .318 
To  secure  greater  durability  in  timbering,  illustrated  and  described  .  .319 
To  support  only  one  overhanging  or  underlying  wall  in  a  drift,  illustrated 
and  described ;  When  the  side  and  roof  need  support,  illustrated  and 

described     ' ....     320 

Placing  the  cross-beam  when  the  pressure  is  equal  on  all  sides  ;  When  the 
side  pressure  predominates  ;  When  the  pressure  is  very  great,  illustrated 
and  described ;    To   prevent  displacement  of  the  posts ;   To  give   the 
frame  still  greater  strength,  illustrated  ;  To  form  caps  and  posts  in  salt 
mines  .         .         .         .         .         .         •         •         •        *         •         •         •     321 

Use  of  ground  sills  when  the  floor  is  loose  and  soft ;  Sills  when  the  frames 
are  near  each  other — When  some  distance  apart ;  Long  sills  illustrated 
and  described  ;  Wedge  braces  for  great  pressures  upon  sills  and  posts  ; 
Position  of  the  frames  according  to  the  pressure  ;  Lining  with  slabs  or  split 
logs  if  the  rock  be  liable  to  crumble ;  Sizes  of  timber  when  the  ground  is 
altogether  crumbling,  or  reopening  of  old  works ;  Timbering  when  a 

loose  face  or  breast  of  a  gallery  is  to  be  opened 322 

Timbering  when  the  sides  are  firm  and  only  the  roof  is  brittle  or  soft,  illus- 
trated and  described ;  When  opening  a  drift  gallery  from  another  and 
timbered  gallery  ;  When  the  floor  of  a  gallery  is  to  be  prepared  for  trans- 
portation and  drainage  ;  Placing  of  cross-beams  in  timbered  and  untim- 

bered  galleries .         .         .         .323 

Timbering  when  the  vein  pitches  considerably,  illustrated  and  described  ; 
Position  and  direction  of  the  floor ;  Testing  the  floor  before  nailing  the 

boards ;    Floors  for  transportation 324 

Timbering  of  shafts .         .         .         .324 

Commencement  of  the  timbering,  illustrated  and  described       .         .         .324 
Temporary  timbering   through   insecure  rock,  illustrated   and   described  5 
Preparing  a  firm  foundation  for   permanent  timbering,  illustrated  and 

described 325 

Construction  of  the  lining  of  shaft  timbering,  illustrated  and  described        .     326 
Timbering  when  all  the  sides  of  a  shaft  do  not  need  it,  illustrated  and 
described ;    Pile  driving,  illustrated  and  described  ;  Timbering  perpen- 
dicular shafts  having  several  divisions    .         .         .         .         .         .         .327 

Complete  timbering  of  the  transporting  gallery,  illustrated  and  described    .     328 
Timbering  of  inclined  shafts  (slopes) 329 


CONTENTS.  Xxi 

PAGE 

Supports  for  the  roof,  illustrated  and  described  ;  Platforms  for  the  partition 

through  which  the  miners  pass,  illustrated 329 

Tramway  or  rail-track  for  transporting  vessels  having  wheels,  illustrated  ; 
Partition  in  transporting  shafts,  illustrated  ;  Need  of  a  shed  at  the  mouth 

of  a  shaft 330 

Timbering  necessary  for  working  in  mines         ......     330 

Preparing  a  timber  ceiling  for  working  overhead,  illustrated  and  described     330 
Timbering  for  working  downwards,  illustrated  and  described  ;  When  taking 
the  ore  from  large  deposits    .          .          .          .          .          .         .          .          .331 

Renewing  timbering         ...         ...         .         .         .         .     331 

Replacing  single  frames,  shaft  timbers,  illustrated  and  described         .         .     332 
Masonry  ............     332 

Classification  of  the  walls  of  the  gallery 332 

Requirements  of  durable  masonry  ;  Most  suitable  building  stones  ;  Prepara- 
tion of  good  common  mortar ;  Of  hydraulic  mortar ;  For  proper  joining 

of  stones 333 

Preparations  before  beginning  a  wall ;  Elements  of  strength  in  the  wall ; 
Building  the  wall,  illustrated  and  described  ;  Arched  masonry  for  great 

strength  and  durability '      .     334 

Proportions  of  the  arch,  illustrated •  '- .  •'    '  .     335 

Semi-circular  arch,  illustrated  and  described ;   An  elliptical  arch,  illustrated 
and  described       .         .         .         .         .         .         .         .         »         ..  *  336 

Construction  of  an  egg-shaped  arch,  illustrated  and  described ;  Construction 

of  an  arched  tunnel,  illustrated  and  described         .         •         *         .         .337 
To  prepare  the  bedding  for  an  arched  wall ;  Treatment  of  the  segments 
when  the  work  on  the  arch  is  interrupted,  illustrated  and  described ;  When 
water  is  found  behind  the  wall ;  Comparative  value  of  dry  and  of  mortar 

walls 338 

Protecting  arched  walls  against  water ;    Illustrations  of  the  various  forms 
of  arches  suited  to  the  conditions  of  the  pressures  from  roof,  sides,  etc. ; 
Drainage  canal  or  sluice  in  main  galleries       .         .         .         .         .         .339 

Joists  for  the  tramway,  illustrated ;  Masonry  for  shafts ;  Temporary  tim- 
bering in  perpendicular  shafts  preceding  the  masonry ;  Main  arches  for 
the  walls,  illustrated  ;  Arches  for  partition  walls,  illustrated  .  .  340 

Masonry  of  shafts  in  swamp  lands ;  Masonry  of  inclined  slopes  or  shafts  ; 
Strength  of  arches  for  walls  of  extended  spaces  ;  Draining  from  the  sides 
of  shafts  341 


xxii  CONTENTS. 


APPENDIX. 

SINKING  ARTESIAN  WELLS. 

PAGE 

Apparatus  for  sinking  artesian  wells ;  Height  of  derricks  used  in  sinking 
wells ;  Weight  of  the  tools  used  at  the  present  time ;  Sizes  of  timber 
used  in  making  derricks  .  .  .  ,  .  .  .  .  *  .  .  343 

Precautions  to  be  used  by  the  workmen ;  Blasdell's  method  of  sinking 
artesian  wells  .  .  ...  .  .  .  ....  .  ,  .  _  .  .  344 

Description  of  pipes  or  tubing  used  in  sinking  artesian  wells ;  To  connect 
.the  pipes  together  in  boring  .  ..  ;  .  .  .  ....  .  345 

Use  of  the  reamer  or  combination  auger  to  enlarge  the  hole  ;  Twist  or 
spiral  auger ;  Iron  rods  furnished  with  male  and  female  socket  joints ; 
Description  of  the  sand  pump  and  manner  of  using  .  ,  .  .  346 

To  hold  the  rods  while  disconnecting  them ;  Description  of  levers  used  to 
force  the  pipe  down;  Valve  sockets  or  "catchalls"  for  catching  the 
rods;  Use  of  steel  dogs  .  . ,  ...  .  .  •».'•'.  .  347 

"Wrench  bar;"  "Boulder-cracker;"  "Spring  catch;"  "Hooks;" 
"Lifter;"  Attaching  a  line  to  the  catchall ;  To  commence  an  artesian 
well *  .  .  .  .348 

Methods  of  overcoming  obstacles  as  sand  gravel,  boulders,  etc. ;  To  obtain 
a  supply  of  water  .  .  .  ...  .  .  .  .  .  349 

Artesian  wells  in  the  vicinity  of  Philadelphia;  Obtaining  water  from 
fissures  and  crevices  in  rocks  ........  350 

OIL  AND  GAS  WELLS. 

Necessary  tools  in  sinking  an  oil  or  gas  well ;  To  start  a  well  where  the 

soil  overlies  the  rock     .  .  .         .         .  .         .  350 

Connecting  the  tools  to  commence  drilling;  Use  of  the  reamer ;  "seed-bag"  351 

Sizes  of  the  wells  drilled .         .         .  352 

353 


PART  I. 


MINING  MINERALOGY, 


AND 


ECONOMIC  TREATMENT  AND  HISTORY  OP  THE 
USEFUL  MINERALS. 


A  PRACTICAL  MANUAL 


OF 


MINERALS,  MINES,  AND  MINING 


MINING  MINERALOGY. 

PRELIMINARY  PRINCIPLES  AND  PREPARATIONS. 

IN  the  successful  study  of  mining  mineralogy  it  is  neces- 
sary to  become  thoroughly  informed  upon  certain  physical 
properties.  A  correct  recognition  of  minerals  does  not, 
however,  demand  a  perfect  knowledge  of  any  one  science, 
as,  for  example,  that  of  crystallography,  or  that  of  the 
chemical  composition  of  even  those  minerals  with  which 
one  may  nevertheless  become  unmistakably  familiar.  Skill 
in  determining  may  depend,  in  a  very  large  degree,  upon 
the  experience  we  may  acquire  by  repeated  examination  of 
well-known  varieties  of  the  same  species.  This  experience, 
however,  demands  that  some  one  shall  have  preceded  us 
with  a  thorough  knowledge  of  chemistry,  in  order  that  the 
analyses  may  decide  that  certain  crystallized  forms  in  min- 
erals, with  certain  specific  gravity,  hardness,  color,  cleavage, 
lustre,  and  some  other  physical  properties,  are  of  a  certain 
specified  or  characteristic  composition.  Chemical  analysis 
alone  can  decide  the  latter  fact,  although  we  may  know  that 


18  MINERALS,    MINES,   AND   MINING. 

certain  mineralogical  compounds  never  crystallize  otherwise 
than  in  certain  forms,  with  a  certain  hardness,  specific 
gravity,  etc. 

For  Example. — We  may  meet  with  a  crystal  which  is 
clear  as  glass,  and  has  six  long  sides,  forming  what  is  desig- 
nated by  the  name  "  prism ;"  this  six-sided  prism,  however, 
terminates  with  a  six-sided  end  or  point,  the  other  end  of 
the  prism  may  be  attached  to  a  rock.  Now  minerals  of 
this  form  have  been  analyzed  and  always  found  to  be 
composed  of  substances  called  silicon  and  oxygen,  in  the 
proportion  of  one  of  the  former  to  two  of  the  latter,  and  as 
this  compound  and  no  other  crystallizes  in  this  form,  we 
know  it  by  this  specific  form  and  call  it  "  quartz." 

Again,  we  may  meet  with  an  equally  transparent  sub- 
stance which,  when  in  crystalline  form,  presents  itself  with 
two  edges,  each  forming  an  acute  angle,  and  two  an  obtuse, 
and  as  a  whole  mass  appearing  under  that  figure  called,  in 
geometry,  a  rhomb.  Its  analysis  shows  it  to  contain  only 
lime  and  carbonic  acid  (dioxide).  The  fact,  therefore,  that 
any  transparent  mineral  presents  such  angles  makes  it 
almost  certain  that  it  is  a  lime  carbonate.  A  knowledge  of 
the  crystalline  forms  under  which  certain  chemical  com- 
pounds present  themselves  frequently  saves  us  the  trouble  of 
analysis. 

CRYSTALLIZATION,  therefore,  is  a  physical  property  of 
minerals  which,  while  it  does  not  always  determine  the 
nature  of  the  substance  before  us,  is  frequently  of  immense 
importance.  The  mineralogist  may  find  a  set  of  crystals 
which,  while  they  have  six  sides  and  are  transparent,  have 


PRINCIPLES   AND   PREPARATIONS.  19 

had  their  ends  broken  off  so  that  he  cannot  certainly  know 
that  they  are  quartz ;  for  lime  carbonate  may  appear  very 
rarely  in  six-sided  crystals,  but  never  in  six-pointed  crystals. 
In  this  case  the  mineralogist  is  forced  to  resort  to  his  acquaint- 
ance with  other  physical  proper  ties,' such  as  we  shall  presently 
introduce. 

As  an  illustration  of  how  important  this  subject  is,  we  may 
state  the  following.  In  1876,  in  Jefferson  Co.,  N.  Y.,  several 
thousand  tons  of  excellent  red  hematite  ore  were  condemned 
because  of  the  appearance  of  large  quantities  of  supposed  min- 
ute quartz  crystals  in  the  ore.  When  visiting  the  mines  we 
discovered  that  the  six-sided  crystals  had  three-sided  termi- 
nations, which  quartz  never  has,  in  place  of  the  six  which 
quartz  always  has.  They  were  therefore  lime  carbonate, 
which  is  an  advantage  in  the  furnace  treatment,  while  quartz 
is  an  injury.  This  distinction  between  three-  and  six-sided 
terminations  led  to  the  immediate  sale  of  the  ore.  If,  how- 
ever, the  terminations  could  not  have  been  seen,  or  we  wished 
to  corroborate  what  the  crystalline  structure  indicated,  we 
must  have  proceeded  to  the  consideration  of  other  properties. 

HARDNESS  as  a  characteristic  comes  in  to  help  in  the 
determination  of  many  minerals.  In  the  illustration  given 
in  the  last  paragraph,  the  crystals  would  have  betrayed  their 
composition  by  their  softness  as  compared  with  quartz.  The 
point  of  a  knife  or  needle  would  readily  scratch  them,  show- 
ing that  in  hardness  they  could  not  be  quartz.  And  so  in 
many  cases  this  property  adds  greatly  to  the  probability  based 
upon  the  crystallization. 

Again,  there  are  certain  lines  of  direction  along  which 


22  MINERALS,   MINES,   AND   MINING. 

the  difference  of  its  weight  in  and  out  of  water,  and  the  quo- 
tient will  be  the  specific  gravity  of  the  mineral. 

Of  course,  the  more  delicate  the  scales,  the  less  in  size 
need  be  the  mass  and  the  more  accurate  will  be  the  specific 
gravity  found.  It  will  sometimes  occur  that  the  mineral,  es- 
pecially if  it  be  rough,  retains  some  bubbles  of  air  upon  its 
surface  materially  altering  the  weight  in  water.  To  prevent 
this,  dip  the  mass  in  alcohol  (if  not  soluble  in  it,  in  any  way) 
and,  afterward,  in  the  water  which  is  to  be  used  for  deter- 
mining the  specific  gravity.  Care  should  be  had  in  suspend- 
ing the  mineral  by  very  light  threads,  silk  threads,  horse- 
hair, or  human  hair,  or  fine  copper  wire  according  to  the 
size  and  weight  of  the  mineral.  Practice  will  give  the  ope- 
rator such  great  skill  in  determining  the  specific  gravity  of 
minerals,  that  where  the  mass  is  of  the  size  of  the  fist,  and 
can  be  readily  poised  in  the  hand,  its  weight  and  specific 
gravity  may  be  closely  approximated.  Thus  the  mineral 
barytes  (sulphate),  or  barite,  frequently  appears  in  masses, 
white,  somewhat  crystalline,  and  to  the  inexperienced  resem- 
bling lime  carbonate,  but  a  piece  taken  into  the  hand  is 
immediately  suspected  by  its  great  weight,  being  in  some 
varieties  twice  as  heavy  as  lime  carbonate.  There  is  no  bet- 
ter method,  at  least  none  more  accurate,  for  determining  the 
bulk  of  a  body  than  by  weighing  the  water  displaced,  as  it 
matters  not  how  irregular  the  mass  may  be  in  surface,  the 
water  will  register  accurately  all  irregularities.  Thus,  if  it 
is  desired  to  ascertain  the  bulk  or  volume  of  the  hand,  take 
a  glass  jar  or  other  vessel,  and  fill  it  with  water  to  the  ex- 
treme edge  of  the  rim.  If  the  glass  be  about  7  inches  high 


PRINCIPLES    AND   PREPARATIONS.  23 

and  12  inches  in  circumference  outside,  it  will  hold  about 
1350  grammes  of  rain-water,  and  be  a  convenient  size  for 
the  trial.  Remove  it  from  the  scales,  after  carefully  weigh- 
ing, and  introduce  the  hand  to  about  the  lower  edge  of  the 
wrist  bone.  This  will  cause  an  overflow  of  water  equal  in 
volume  to  that  of  the  hand.  Remove  the  hand,  wipe  the 
glass  outside  and  replace  the  glass  in  the  scales  with  its  re- 
maining water,  and  weigh  it  again.  Subtract  the  latter 
weight  from  the  former  and  you  have  the  exact  amount  of 
water  displaced  and  the  bulk  of  the  hand  as  introduced. 
Now  if  you  know  the  weight  of  a  cubic  inch  of  that  water 
displaced,  divide  the  cubic  inch  weight  into  the  weight  of 
the  bulk  displaced,  and  you  have  the  exact  size  or  bulk  of 
the  hand.  As  an  example  in  an  actual  case  of  a  medium 
hand  of  a  man  whose  height  was  medium — 

Glass  full  of  water  =  1338  grammes 

Glass  after  introduction  of  the  hand  =     942 

loss          396  grammes 

=  weight  of  the  hand  volume  of  water.     The  volume  of 
this  amount  may  be  found  thus  : — 

252.432  grains  of  pure  rain-water  =  16.359  grammes  = 
weight  of  one  cubic  inch  of  water  at  60°  F.  and  30  inches 
height  of  barometer.  We  need  not  be  so  accurate  in  this 
case,  so  we  may  say  that  a  cubic  inch  of  pure  rain-water 
weighs  16  grammes,  therefore  396  grammes  divided  by  16 
gives  24  cubic  inches,  accurately  24.7  cubic  inches,  as  the 
cubical  size  of  the  hand.  Now,  as  human  flesh  and  bone  is 
only  a  little  over  the  specific  gravity  of  water,  we  may  con- 


24  MINERALS,   MINES,    AND   MINING. 

sider  the  hand  as  1.1,  or  one-tenth  heavier  than  the  same 
bulk  of  water,  so  that,  as  396  +  39.6  =  435.6  grammes, 
and  as  the  latter  amount  in  grains,  at  15.432  grains  to  one 
gramme,  equals  6722  grains,  and  as  437.5  grains  are  equal  to 
one  ounce  avoirdupois,  we  shall  have  15.36  ounces  as  the 
weight  of  a  man's  hand,  or  nearly  15|  ounces  in  this  case. 
The  medium  hand  of  a  child  displaces  about  222  grammes, 
and  is  about  8  ounces  and  nearly  six-tenths  of  an  ounce. 
This  is  only  approximate  in  the  details,  but  exhibits  the 
method  and  suggests  some  uses. 

When  great  accuracy  is  required,  it  is  necessary  to  obtain 
carefully  distilled  water ;  make  the  temperature  60°  F.  and 
make  corrections  of  barometer  for  any  variation  from  30  inches 
of  height,  for  it  is  seldom  that  the  barometer  is  at  that  height. 
In  most  cases  the  latter  variation  is  not  very  important,  and 
indeed  attention  to  it  may  be  entirely  neglected  except  where 
standard  trials  and  corrections  of  standards  are  to  be  made, 
and  the  same  is  true  in  regard  to  water ;  good,  clear,  and 
pure  rain-water  may  be  used  for  most  trials  at  any  tempera- 
ture between  50°  and  75°,  without  much  inaccuracy,  for  it 
is  seldom  that  any  two  minerals  of  even  the  same  species  are 
of  exactly  the  same  specific  gravity,  or,  so  nearly  the  same 
as  to  require  the  accurate  determination  with  distilled  water, 
temperature  60°  and  barometrical  height  of  30  inches. 

If  we  take  the  specific  gravity  of  water  in  a  thousand  grain- 
bottle,  which  is  the  best  for  ordinary  delicate  scales,  at  52° 
and  at  80°,  the  difference  will  be  but  small ;  thus,  with  an 
extremely  delicate  pair  of  Becker  &  Son's  scales,  we  took 
the  specific  gravity  of  1000  grains  good  rain-water  at  52° 


PRINCIPLES   AND   PREPARATIONS.  25 

and  its  weight  was  found  to  be  64.775  grammes.  The  water 
was  again  taken  in  a  few  minutes  at  79°  F.,  when  it  was 
found  to  be  64.604,  being  a  difference  of  not  quite  0.28  per 
cent.,  not  quite  three-tenths  of  one  per  cent.  On  heating  to 
95°  F.,  the  weight  decreased  to  64.378  grammes  or  0.62  of 
1  per  cent.,  and  on  continuing  heating  to  99°,  we  may  say 
100°  (as  the  temperatures  were  not  taken  till  immediately 
after  the  weight  was  taken),  the  weight  was  then  decreased 
to  64.333  grammes,  equal  to  about  0.69,  or  nearly  0.7  of  one 
per  cent.  In  all  these  trials  the  barometer  remained  at  the 
same  height,  namely,  28.27  inches. 

Now,  if  we  take  the  same  water,  we  may  find  the  differ- 
ence more  important  when  we  wish  to  find  the  specific  grav- 
ity of  a  mineral  or  metal,  under  differing  degrees  of  temper- 
ature. The  following  actual  experiment  will  illustrate  the 
variations.  A  piece  of  native  silver  from  mines  near  Onta- 
nagon,  Lake  Superior,  was  introduced  into  the  water  at  a 
temperature  of  40°  F.  at  first,  and  the  following  table  will 
show  the  variations  afterward  as  the  temperature  was  in- 
creased : — 

Per  cent,  of 
Increase.         increase. 
Water  at    40°      Specific  gravity  7.775 

Water  at    61°.5         "          "  7.817  .042  .540 

Water  at    79°  "  "  8.077  .260  3.326 

Water  at  105°  "  "  8.639  .562  6.958 

We  have  taken  temperatures  at  about  20°  F.  increase 
for  each  experiment,  and  it  will  readily  be  seen,  that  after 
60°,  the  increased  temperature  of  the  water  rapidly  increases 
the  specific  gravity.  The  piece  of  native  silver  had  a  little 
native  copper  in  its  irregular  and  rugged  sides  which  de- 


26  MINERALS,   MINES,   AND   MINING. 

creased  the  specific  gravity.  When  the  native  silver  is  en- 
tirely free  from  other  metals  its  specific  gravity  is  generally 
9.5  to  10,  and  when  pure,  10.5. 

It  is  plain  that  care  must  be  taken  in  proportion  to  the 
degree  of  accuracy  desired  and,  from  the  above  remarks  and 
illustrations,  the  student  may  be  able  to  form  his  own  judg- 
ment as  to  the  degree  of  care  to  be  taken  in  finding  any 
specific  gravity. 

A  practical  knowledge  of  this  subject  becomes,  on  some 
occasions,  of  very  great  importance  to  the  miner  and  artisan, 
or  builder.  A  block  of  stone  or  marble,  lump  of  coal,  ore, 
etc.,  may  be  weighed  without  scales,  for  if  we  know  the  spe- 
cific gravity  of  the  material  we  can  compare  the  cubic  con- 
tents of  the  mass  we  wish  to  weigh,  with  the  same  mass  of 
water  and  we  shall  learn  its  weight.  Thus,  I  have  a  rect- 
angular block  of  marble  five  feet  long  and  three  feet  high, 
being  three  broad,  or  wide,  sides  all  straight :  now  5x3 
=  15  x  3  =  45  cubic  feet.  I  find  that  the  specific  gravity 
of  that  marble  is  2.5,  that  is  it  is  more  than  twice  as  heavy 
as  water  by  0.5.  Now  a  cubic  foot  of  pure  water  weighs 
very  nearly  62|  pounds,  and  twice  and  a  half  62|  pounds 
are  156.25  pounds  to  every  cubic  foot  of  the  marble,  which 
weight  multiplied  by  45  =  7031  pounds  weight  for  that 
block  of  marble.  Different  specimens  of  the  same  species 
of  ore  may  vary  in  specific  gravity,  in  which  case  a  small 
piece  may  be  broken  off  and  its  specific  gravity  determined, 
from  which  the  weight  of  the  mass  may  be  determined. 
But  the  sides  of  the  block  may  be  uneven  and  greater  care 
must  then  be  taken  in  measuring. 


THE  BLOWPIPE.  27 

THE  BLOWPIPE. 

Another  very  important  aid  in  determining  mineral  sub- 
stances is  that  furnished  by  the  BLOWPIPE. 

The  philosophy  of  its  action  depends  largely  upon  the 
fact  that  the  usual  candle  flame,  and  somewhat  similar  flames, 
may,  by  means  of  the  blowpipe,  be  directed  upon  an  assay 
in  minute  pieces,  so  that  either  that  part  called  the  inner 
flame,  or  that  called  the  outer  flame,  may,  at  will,  be  brought 
to  bear  upon  the  mineral  to  be  assayed.  The  inner  flame, 
generally  that  of  blueish  hue,  is  the  deoxygenating  flame, 
the  outer,  the  oxygenating  flame.  It  also  depends  for  its 
efficiency  upon  the  chemical  fact  that  some  minerals  are  read- 
ily altered,  under  certain  conditions,  in  color,  form,  or  com- 
position, according  to  the  nature  of  the  flame  directed  upon 
them. 

Blowpipes  should  be  neat  and  small,  or  light  and  not  com- 
plicated. Any  practicer  can,  and  should,  learn  to  blow  with- 
out introducing  any  saliva  into  his  blowpipe.  This  result 
can  always  be  accomplished ;  hence,  all  bulbs,  reservoirs, 
etc.,  upon  the  blowpipe,  are  unnecessary  complications. 
Charcoal  should  be  cut  from  pieces  made  from  young 
branches  of  any  wood  which  is  hard  and  close  grained  and 
may  be  cut  in  blocks  an  inch  square  and  as  thick,  or  into 
slips  or  rods,  two  or  three  inches  long  and  half  to  three- 
quarters  inch  wide,  and  half  as  thick ;  one  end  to  be  covered 
with  paper,  pasted  on,  or  wrapped  around  after  being  wet, 
and  then  gummed  along  an  edge.  The  square  blocks  may 
be  wired,  or,  in  travelling,  held  on  the  point  of  a  wire,  or 


28  MINERALS,   MINES,   AND    MINING. 

knife  blade.  We  are  now  regarding  strictly  the  simplest 
efficient  collection  of  materials  for  blowpipe  practice. 

A  candle  is  sufficient,  or  a  little  tin  lamp  for  either  alcohol 
or  sweet  oil ;  a  cork,  with  a  hole  in  the  cork,  and  fitting 
over  the  wick  tube,  will  answer  the  demands,  even  with  alco- 
hol, pretty  well.  A  glass  stopped  alcoholic  lamp  is  larger 
and  better  looking  and  preferable,  if  it  is  to  be  used  at  home, 
or  can  be  safely  kept  in  the  box  of  the  travelling  student,  or 
mineralogist. 

Common  sal-soda,  which  has  stood  exposed  to  the  air  till 
it  has  effloresced,  is  a  very  good  soda  salt  and,  though  not 
always  pure,  may  be  obtained  so  nearly  pure  as  to  serve  for 
most  purposes  as  a  soda  carbonate. 

Borax  should  be  pulverized,  so  that  it  may  be  picked  up 
by  the  loop  of  the  platinum  wire. 

Platinum  wire  should  be  nearly  as  thin  as  an  ordinary 
horse-hair,  or  thinner,  and  may  be  wrapped  around  a  little 
hard  wood  stem  for  a  handle,  as  large  round  as  an  ordinary 
match,  and,  indeed,  the  loop  at  the  end  may  be  formed  by 
placing  the  end  of  the  wire  against  a  round  match  and  roll- 
ing both  round  between  finger  and  thumb,  and,  when  the 
loop  has  been  formed,  the  match  may  be  drawn  away  through 
the  wire,  leaving  the  loop. 

Microcosmic  salt,  the  usual  name  of  phosphate  of  soda  and 
ammonia,  may  be  made  by  gently  heating  together  (in  dis- 
tilled water)  100  parts,  by  weight,  of  crystallized  phosphate 
of  soda  with  16  parts  chloride  of  ammonium,  or  clean  sal 
ammoniac,  filter  and  evaporate  and  preserve  the  crystals  in 


PREPARATORY   PRACTICE.  29 

a  bottle.  This  salt,  when  heated,  has  the  power  of  dissolv- 
ing almost  every  chemical  compound. 

The  above,  with  four  or  five  inches  of  small  hard  glass 
tubing,  the  size  of  a  large  goose-quill,  comprise  the  essen- 
tials for  beginning  the  experiments  with  the  blowpipe,  and, 
indeed,  for  the  usual  work  of  the  student  it  would  be  better 
to  get  nothing  more  until  he  is  expert  in  the  use  of  these 
alone. 

PREPARATORY  PRACTICE 

with  the  BLOWPIPE  demands  more  or  less  time  with  different 
individuals ;  but  apparent  lack  of  skillfulness  at  first  use  is 
no  proof  that  the  practicer  will  not  become  an  expert. 

HINTS. — Any  strange  taste  invites  saliva ;  after  awhile  the 
presence  of  the  blowpipe  becomes  no  longer  singular,  but 
easy  and  natural,  and  the  student  may  use  for  hours  an  in- 
strument without  any  trouble  from  saliva,  and  his  practice 
be  clean  and  taste  perfectly  natural. 

A  small  loop  picks  up  so  much  of  the  reagent  as  can  be 
easily  managed  under  the  usual  blowpipe  flame  and  practice 
which  should  be  adopted  at  the  time  of  the  first  experiments. 
Too  large  a  "  bead"  results  from  too  large  a  loop,  and  this 
fatigues  the  operator  not  only,  but  the  reduction  of  the 
mineral  cannot,  in  the  same  time,  be  so  perfect,  and,  hence, 
not  so  satisfactory,  especially  to  the  beginner. 

Learn  to  blow  easily  and  continuously.  The  only  method 
we  can  suggest  to  aid  in  learning  this  art  is,  first,  to  take 
the  mouth  full  of  water  and,  holding  it,  breathe  regularly 
entirely  through  the  nose  by  inhalation  and  exhalation. 


30  MINERALS,   MINES,   AND   MINING. 

Next,  discharge  the  water  and  do  the  same  with  the  mouth 
full  of  air,  allowing  a  very  little  to  escape  all  the  time. 
Next  is  the  supplying  of  air  to  this  reservoir  of  mouth  and 
cheek.  This  is  an  art  so  concealed  in  the  mouth  that  no 
teacher  can  exactly  instruct  any  student  to  accomplish  the 
work  so  well  as  he  can  learn  by  a  little  practice.  After  a 
while  the  strange  lesson  becomes  perfectly  easy.  Continu- 
ous blowing,  or  rather  a  continuous  stream  of  air,  is  neces- 
sary in  some  experiments  for  keeping  the  inner,  or  deoxy- 
genating  flame  constantly  on  the  object  to  be  deprived  of  its 
oxygen,  or,  as  we  shall  call  it,  the  "assay,"  for,  if  the  outer 
flame  touches  the  assay,  it  will  again  be  oxygenated,  and, 
vice  versa.)  the  rapid  oxygenating  of  an  assay  requiring  con- 
stant blowing  without  intermitting.  For  this  and  other 
reasons  the  ability  to  blow  a  constant  flame  is  desirable. 

FOR  PRACTICE. — Upon  an  even  part  of  a  close-grained 
piece  of  charcoal,  place,  with  the  end  of  a  pen-knife,  a  little 
common  litharge  (lead  oxide)  and  the  same  amount  of  car- 
bonate of  soda.  Turn  the  inner  flame  (hereafter  written 
I.  F.)  very  gently  upon  it,  and  you  will  soon  succeed  in  re- 
ducing it  to  metallic  lead,  and,  for  practice,  see  if  the  lead 
can  be  kept  in  a  metallic  globule  by  continuing  the  I.  F. 
Turn  the  outer  flame  (hereafter  written  O.  F.)  upon  it  and 
volatilize  the  lead,  and  partly  by  changing  it  back  into  lead 
oxide,  leaving  an  outer  rim  or  border  upon  the  charcoal  of  a 
dingy  yellowish  brown  (lead  oxide).  Study  this  color  as  the 
"lead-orange." 

Place  upon  a  similar  piece  of  coal  in  a  similar  way  a  piece 
of  metallic  zinc.  Turn  the  O.  F.  upon  it ;  notice  the  pecu- 


PREPARATORY   PRACTICE.  31 

liar  flaky  specks  and  minute  detachments ;  notice,  also,  the 
peculiar  canary-yellow  which  the  flaky  masses  assume  and 
retain  while  liot,  and  which  become  changed  to  pure  white 
on  cooling  ;  notice,  also,  the  peculiar  phosphorescence  which 
the  flaky  mass  or  oxide  of  zinc  assumes  when  strongly 
heated.  Try  a  little  tin  and  notice  that  although  it  leaves  a 
white  oxide,  it  is  the  same,  hot  or  cold,  and  has  no  phosphor- 
escence. Take  the  platinum  wire ;  make  a  loop,  heat  the 
loop  bright  red-hot,  and  quickly  dip  it  into  powdered  borax ; 
turn  the  flame  (either  O.  or  I.)  upon  the  mass ;  notice  the 
intumescence  due  to  escaping  of  the  "  water  of  crystalliza- 
tion;" blow  till  the  bead  becomes  pure  and  entirely  trans- 
parent and  absolutely  colorless.  If  there  is  the  slightest 
tinge  the  borax  bead  is  impure,  and  the  cause  must  be 
sought  for — if  in  the  borax,  a  fresh  supply  of  better  borax 
must  be  got. 

Dip  the  platinum  loop  (newly  provided  with  a  clear  borax 
bead,  as  last  mentioned,  or  heat  the  same  bead  last  made,  if 
clean  and  clear)  into  a  little  charcoal  dust,  or  blow  a  little 
smoke  of  the  flame  upon  it ;  then  turn  the  O.  F.  upon  it  and 
burn  it  clean  and  clear,  and  remember  that  any  organic 
matter  may  be  thus  burned,  or  oxidated  by  the  oxygenating 
flame  (O.  F.),  until  the  black  entirely  disappears.  Heat  the 
bead  once  more  to  a  red  heat ;  have  prepared  beforehand  a 
speck  of  black  oxide  of  manganese,  about  the  size  of  the 
point  of  a  pin,  upon  a  piece  of  glass,  or,  better,  broken  por- 
celain plate ;  quickly  press  the  red-hot  bead  upon  the  speck 
of  oxide  of  manganese,  turn  the  O.  F.  upon  it,  watching 
sharply  the  red-hot,  or  white-hot,  bead,  and  notice  that  the 


32  MINERALS,   MINES,   AND   MINING. 

circulating  oxide  is  gradually  becoming  mixed  with  the 
borax,  and  the  bead  has  a  peculiar  homogeneous  dark  reddish 
appearance ;  stop  and  hold  before  a  white  sheet  or  wall,  or 
up  to  a  strong  light ;  the  color  is  amethystine ;  this  is  the 
44  characteristic  color"  of  manganese,  if  not  too  much  adul- 
terated with  iron  or  other  metals :  study  this  color.  Then 
turn  the  I.  F.  (deoxygenating  flame)  upon  the  same  bead ; 
watch  the  bead  in  the  flame ;  it  acquires  a  kind  of  reddish 
transparency,  and  a  little  attention  will  enable  the  student 
to  see  a  decided  change,  and,  if  the  deoxygenation  has  taken 
place,  then,  on  cooling,  the  bead  will  be  perfectly  color- 
less. Now  heat  red  hot,  as  at  first,  but  with  the  O.  F.,  and 
after  a  short  time  the  color  returns  ;  touch  the  red-hot  ball 
to  another  speck  of  manganesian  oxide  and  thoroughly 
oxygenize.  On  cooling  it  is  darker ;  repeat  the  process  of 
adding  till  the  bead,  after  cooling,  from  the  O.  F.  is  almost 
black ;  heat,  now,  red  hot,  and,  while  hot,  mash  the  bead 
flat  against  the  glass  plate,  or  any  hard  surface,  and  with  the 
stem  of  the  blowpipe.  Hold  it  up  to  the  light  and  notice 
that,  although  apparently  black,  it  is  now  transparent  and 
deep  violet  or  amethystine :  remember  this  process  for  future 
beads. 

To  remove  the  bead,  notice  which  part  of  the  loop  has  the 
end  of  the  wire,  turn  that  end  uppermost,  then,  holding  the 
wire  stem  firmly  with  the  left  hand,  and  pinching  the  cold 
bead  firmly  between  the  finger  arid  thumb  of  the  right  hand, 
draw  the  bead  away  from  the  left  hand,  while,  at  the  same 
time,  the  thumb  and  finger  of  the  right  hand  are  turned 
over  from  the  left  to  the  right,  the  loop  will  thereby  be 


PREPARATORY   PRACTICE.  33 

opened,  and  the  wire  will  leave  the  bead  in  the  grasp  of  the 
fingers  while  the  wire  is  being  straightened  out.  A  little 
practice  will  enable  the  pupil  to  become  expert  in  removing 
the  beads,  which  may  be  preserved  in  a  little  clear  glass  dram 
vial  for  reference.  If  not  desired  for  the  future,  and  there 
is  no  haste  to  rid  the  wire  of  them,  the  beads  may  be  either 
melted  and  instantly  jarred  off  or  the  wire  may  be  dropped 
into  a  glass  of  water,  and  in  about  fifteen  or  twenty  minutes 
the  bead  will  dissolve  off. 

Lenses  are  frequently  necessary,  either  in  the  form  of 
pocket  single  lenses  of  half  an  inch,  or  one  inch,  focus  (the 
latter  power  is  most  used),  or  the  finer  style  of  compound 
lenses  in  brass  or  other  metal  case.  Caution  :  Never  reduce 
a  metal  upon  platinum  wire,  as  the  heat  will  cause  the  metal 
to  alloy  with  the  platinum,  and  the  alloy  will  melt  and  the 
wire  be  injured.  In  using  borax  the  reduced  metal  may 
sometimes  be  kept  off  the  wire,  as  when  the  experiment 
with  litharge  was  made,  but  it  is  not  safe.  Use  charcoal. 

MAGNETISM  is  a  help  in  determining  some  minerals,  and 
the  most  convenient  method  of  applying  it  is  by  means  of  a 
little  pocket  compass,  or  a  magnetized  pocket-knife  blade, 
by  which  any  small  specks  of  supposed  magnetic  sand,  or 
other  ore,  may  be  determined  instantly,  at  home  or  wherever 
the  mineralogist  may  be  travelling. 

We  would  advise  the  learner  to  experiment,  as  above 
directed,  until  quite  expert  before  trying  to  proceed  upon  the 
blowpipe  indications  hereafter  stated. 

CUPELLATION. — This  strictly  belongs  to  the  separation  of 
some  metals,  but  the  practical  mineralogist  frequently  needs 


34  MINERALS,    MINES,   AND   MINING. 

the  knowledge  of  the  process,  and  he  may  make  great  use 
of  it  in  determining  the  nature  and  comparative  value  of 
some  ores.  Even  with  the  blowpipe  the  process  is  frequently 
useful. 

A  cupel  is  the  common  name  for  a  circular  block  of  bone- 
ash  with  a  small  depression  in  the  upper  surface.  It  may 
be  of  any  size  or  shape,  but  for  usual  assay  purposes  a  cupel 
is  generally  an  inch  or  more  in  diameter  and  half  an  inch 
thick,  and  cupels  may  be  obtained  so  readily  at  any  manu- 
facturing chemist's  salesroom  that  it  is  not  economy  to  make 
them,  and  they  can  be  sent  and  received  by  mail.  When 
these  cupels  are  sufficiently  heated  (red  hot)  with  a  little 
lead  they  have  the  property  of  absorbing  the  lead,  which  is 
changed  into  the  form  of  a  liquid  lead  oxide.  At  the  same 
time  any  melted  gold  or  silver  which  was  in  the  lead  remains 
upon  the  surface  of  the  cupel  in  the  shape  of  a  bright  ball 
or  button,  which  brightened  instantly  when  the  lead  had  en- 
tirely disappeared  from  its  surface. 

It  is  necessary,  therefore,  to  have  a  furnace  prepared  to 
receive  an  arched  clay  box,  or  small  chamber  called  "a 
muffle,"  which  shall  be  fitted  to  receive  the  cupels,  so  as  to 
protect  them  from  the  surrounding  fire  when  the  muffle  is 
heated  to  a  low  red  heat. 

Of  course,  in  the  convenience  of  the  laboratory  and  at 
home  the  best  method  is  to  obtain  the  small  clay  furnace 
already  prepared  for  this  purpose.  But  where  this  furnace 
cannot  be  had  a  cylindrical  sheet-iron  stove  will  answer ; 
line  it  with  even  the  common  red  bricks ;  put  the  draft  door 
below  and  the  grate  just  above  it,  with  a  hole  (ten  or  twelve 


IN   REVIEW.  35 

inches  above  the  grate)  sufficiently  large  for  the  entrance  of 
the  muffle,  and  a  small  hole  broken,  before  lining,  in  the 
brick  lining  opposite  the  hole,  with  sufficient  length  upward 
of  the  sheet  iron  to  allow  the  covering  of  the  muffle  above 
with  coal  to  a  height  of  at  least  four  inches,  and  have  a 
movable  cover  to  the  stove.  This  extemporized  furnace  will, 
with  a  practical  operator,  produce  all  that  can  be  desired. 
We  have  for  years  used  such  a  furnace  with  excellent  re- 
sults. The  figure  of  a  larger  furnace  for  crucible  work  as 
well  as  for  cupelling  is  given  at  the  close  of  the  description 
of  reagents. 

When,  however,  the  assay  is  very  small  and  the  mineralo- 
gist chooses  to  use  his  blowpipe,  he  may  make  a  little  cavity 
in  his  charcoal  and  fill  it  with  bone-ash,  moistened  and 
pressed  neatly  down,  and  upon  this  he  may  separate  gold  or 
silver  from  the  lead,  and  with  a  little  pure  nitric  acid  in  a 
test-tube  dissolve  the  silver,  leaving  the  gold  deposit  as 
minute  dark  powder  at  the  bottom  of  his  test-tube,  to  be 
washed,  dried,  and  returned  to  the  charcoal,  and  melted  to 
a  globule  of  gold. 

In  Review. 

The  reader  should  know  that  we  have  presented  only  that 
which  shall  be  of  most  practical  use  in  general,  but  particu- 
lar applications  will  be  given  hereafter.  Still  it  is,  for  more 
rapid  progress,  better  that  the  suggestions  already  made 
should  be  followed  out  in  actual  work.  No  amount  of 
instruction  can  take  the  place  of  actual  experiment.  A 
little  practice  will  remove  apparent  difficulties.  Especially 


36  MINERALS,    MINES,    AND    MINING. 

are  the  experiments  with  the  blow-pipe  to  be  made,  until  a 
degree  of  expertness  is  acquired  before  attempting  to  pro- 
ceed to  the  subsequent  parts  of  this  work. 

For  specific  gravity  a  pair  of  scales  may  commonly  be 
used  which  may  be  ]oaded  to  the  amount  of  six  or  eight 
ounces,  and  sensitive  to  a  grain.  In  delicate  analyses  one 
more  sensitive  must  be  employed.  No  time,  at  first,  is  lost 
by  attempting  various  experiments  and  other  work,  since 
expertness  in  the  use  of  apparatus  conduces  to  accuracy  and 
rapidity  when  useful  and  necessary  work  is  undertaken,  and 
such  expertness  is  to  be  acquired  only  by  practice. 

Out  of  the  vast  number  of  crystal-forms  only  compara- 
tively a  few  are  of  importance  to  the  mining  mineralogist, 
and  these  forms  are  best  studied  from  actual  specimens. 

But  after  all  knowledge  of  the  facts  stated  in  the  preced- 
ing pages  many  minerals  are  found  which  require  other 
treatment  before  they  will  disclose  their  compositions,  either 
as  to  quality  or  quantity.  We  shall,  therefore,  proceed  to 
the  study  of  what  is  called  chemical  analysis,  stating  at  first 
certain  principles  a  knowledge  of  which  will  render  it  more 
easy  to  study  the  practice. 

All  material  substances  are  composed  of  a  limited  number 
of  what  are  supposed  to  be  simple  or  uncompounded  bodies 
called  elements.  At  present,  discovery  announces  only 
about  66.  In  useful  mineralogy  there  is  special  interest  in 
only  about  40. 

But  the  most  important  fact  connected  with  these  ele- 
ments is  that  they  combine  with  each  other  in  certain  defi- 
nite and  unalterable  proportions.  For  example,  iron  as  an 


IN    REVIEW.  37 

element  is  not  only  purely  and  simply  iron,  but  when  it 
combines  with  the  element  oxygen,  it  does  so  in  a  proportion 
of  56  of  iron  to  16  of  oxygen,  never  in  less  proportion  than 
56.  If  more  iron  combines  with  oxygen  it  will  combine 
only  as  twice  56  or  112  to  a  multiple  of  1.6,. in  this  case 
three  times  16  or  48,  or  if  in  any  other  combination  it 
always  acts  as  though  56  was  its  characteristic  number.  So 
it  is  with  oxygen  and  the  number  16,  and  so  it  is  with  every 
one  of  the  elements  and  a  definite  number.  Each  element 
has  its  own  unchangeable  combining  number,  or  "atomic 
weight." 

It  is,  therefore,  a  matter  of  the  highest  value  .to  determine 
the  combining  number  of  the  elements,  and  chemists  have 
in  some  cases  devoted  much  time  to  this  work. 

Taking  the  same  example  of  iron  and  oxygen,  the  union 
of  the  two  in  a  compound  mass  of  iron,  called  iron  oxide,  is 
precisely  as  though  the  mass  were  made  up  of  56  parts  of 
iron  and  16  parts  of  oxygen.  If  this  be  so  in  any  one  mass, 
it  becomes  very  easy,  by  finding  the  amount  of  one  element 
in  that  mass,  to  determine  the  amount  of  the  other.  Sup- 
pose I  find  that  the  element  iron  is  present  in  the  mass  of 
pure  oxide  of  iron  to  the  amount  of  a  certain  number  of 
grains  or  pounds,  then  the  oxygen  is  easily  found,  and  the 
per  cent,  of  pure  iron  to  the  mass,  as  we  shall  show  hereafter. 

Chemists  have  abbreviated  the  names  of  elements  by 
symbols  for  convenience  sake,  and  these  symbols  appear  in 
the  table  which  follows.  Combining  weights  are  sometimes 
called  atomic  weights  or  equivalents,  or  combining  numbers. 


38 


MINERALS,    MINES,   AND   MINING. 


Combining  Weights  of  Elementary  Bodies. 


Those  in 
Aluminum      .     . 
Antimony  .     .     . 
Arsenic 
Barium 
Bismuth     .     .     . 
Boron    .... 

brackets  are  not  as  ye 
.  Al      27.5  (?) 
.  Sb    122.(?) 
.  As      75. 
.  Ba    137. 
.  Bi    208. 
.Bo     11 

t  applied  to  any 
Molybdenum 
Nickel  .     . 

useful  purposes. 
.     .  Mo     92?  95.5 
.     .     .  Ni      58  7  ?  57.9 

[Niobium] 
Nitrogen    . 
[Osmium]  . 
Oxygen 
Palladium  . 
Phosphorus 
Platinum    . 
Potassium  . 
[Rhodium] 
[Rubidium] 
[Ruthenium] 
[Scandium] 
[Selenium] 
Silicon 

.     .     .   Nb     93.8 
.-  ...     .  N       14. 
.  .  .     .  Os    199.2?  198.5 
.  .  .     .  O       16. 
.     .     .  Pa    106.6?  105.7 
.     .     .  Ph     31. 
.     .     .  Pt    197?  194.4 
.     .     .   K      39.13?  39.01 
.     .     .  Rh   104.0 
.     .     .   Rb     85.4 
.     .     .  Ru   104. 
.     .     .   Sc      44. 
.     .     .   Se      79. 
Si         2R    98  9 

Bromine     . 
Cadmium  .     .     . 
Caasium      .     . 
Calcium     .     .     . 

.  Br     80. 
.  Cd    112. 
.  Cs     133. 
.  Ca      40. 
.  C        12. 

.  Ce      92. 

Chlorine     .     .     . 
Chromium  .     .     . 
Cobalt  .... 

.  Cl       35.5 
.  Cr      52.5 
.  Co      59 

.  Cu     63  5 

[Didymium]  .     . 
[Erbium]  .     .     . 
Fluorine     . 
[Galium]    .     .     . 
[Glucinum]     .     . 
Gold      .... 

.  Di      96. 
.  E        ? 
.  Fl      19. 
.    ?        ? 
.  Gl        9. 
Au  197 

Silver  -. 

.  Ao1   108    107  7 

Sodium 
Strontium  . 
Sulphur 
[Tantalum] 
[Tellurium] 
[Thallium] 
[Thorium] 
Tin 

.     .     .  Na     23. 
.     .     .   Sr      87.5 
.     .     .  S        32. 
.     .     .  Ta   182.6 
.     .     .  Te    129?  128 
.     .     .  Tl    203. 
.     .     .  Th  233.4 

On      1  1  Q     1177 

Hydrogen  .     .     . 
[Indium]    .     .     . 
Iodine  .... 

.  H        1. 
.In      74?  113.4? 
.  I       126.8 

Iridium 
Iron 

.  Ir      198?  192? 

V&        *ifif  *}**  Q1  ^ 

Titanium    . 
Tungsten   . 
Uranium    . 
[Vanadium] 
[Ytterbium] 
[Yttrium]  . 
Zinc 

.     .     .  Ti       50  ?  48 
.     .    \.  W    183. 
.     .      .  U     237?  238 
.     .     .   V     137?51.2 
.     .     .  Yb  172.8 
.     .     .  Y       89.8 
.         Zn     65 

[Lanthanum]  .     . 
Lead     .... 

.La      92?  138.5. 
.  Pb    207   206  4 

[Lithium]  .     .     . 
Magnesium      .     . 
Manganese      .     . 
Mercury     .     .     . 

.  Li         7. 
.  Mg     24. 
.  Mn     55(53.9?) 
.  Hg  200. 

'Zirconium] 

.     .     .  Zr     89.4 

TABLE   OF   ATOMIC   WEIGHTS.  39 

Note. — Some  of  the  atomic  weights  in  this  list  are  taken 
from  the  most  recent  edition  of  Fresenius,  as  found  in  his 
quantitative  tables  in  the  recent  edition  by  Johnson.  But 
the  editor  of  that  treatise  doubts  the  weights  of  aluminum 
and  antimony,  and  thinks  that  they  should  be  120  and  27.2 
respectively,  but  as  they  have  been  used  as  122  and  27.50, 
these  numbers  are  retained.  Where  numbers  are  not  in  ac- 
cordance with  recent  discovery  we  have  added  the  more  recent. 

Comparatively  few  of  the  66  elementary  bodies  have  had 
their  atomic  weights,  or  what  might  more  correctly  be  called 
their  combining  weights,  certainly  determined.  Perhaps  those 
which  have  been  accurately  determined  are  only  hydrogen, 
oxygen,  nitrogen,  chlorine,  bromine,  iodine,  lithium,  potas- 
sium, sodium,  silver,  and  thallium,  as  follows:  H  1,  O 
15.9633,  N  14.0210,  Cl  35.3700,  Br  79.7680, 1  126.5570, 
Li  7.0073,  K  39.0190,  Na  22.9980,  Ag  107.6750,  Tl 
203.7150.  Manganese  has  recently  been  determined  as 
53.9  rather  than  55  as  in  Fresenius,  and  molybdenum  95.5 
instead  of  92.  The  weights,  as  given  in  the  recent  edition 
of  the  Enc.  Brit.,  "Chemistry,"  are,  in  many  cases,  at  variance 
with  more  recent  examinations.  Our  list  is  as  nearly  accu- 
rate as  can  be  determined  at  present  with  the  corrections  we 
have  suggested  above. 

THE  PRACTICAL  USE  OF  THE  TABLE  OF  ATOMIC 
WEIGHTS. 

The  student  may  as  easily  learn  to  compute  his  "  sought" 
elements  from  his  "  found"  by  using  the  table  of  atomic 
weights,  as  by  the  use  of  any  other  table,  provided  that  he 


40  MINERALS,   MINES,   AND   MINING. 

be    careful  in  his  calculations.     He   may   proceed    as    fol- 
lows : — 

Suppose  he  has  found  20  grains  to  be  the  weight  of  per- 
oxide of  iron  in  an  assay  (ferric  oxide)  Fe2O3,  and  he  seeks 
for  pure  iron.  In  the  table,  Fe  is  56,  Fe  x  2  =  112.  O  is 
16,  and  Ox  3—48.  Therefore  the  atomic  weight  of 
Fe2O3,  as  a  whole,  is  112  +  48  or  160;  this  number  is  the 
theoretic  whole,  and  is  equivalent  to  the  100  per  cent,  of 
which  100  per  cent.  Fe2  is  the  part  sought.  So  the  propor- 
tion is  160  :  112  ::  20  :  14  grains  for  actual  weight  of  iron ; 
or  160  :  112  : :  100  :  70  for  simply  the  per  cent,  of  iron. 

Again,  the  per  cent,  of  any  one  compound  of  an  assay,  if 
known,  makes  it  easier  to  calculate  the  composition  of  the 
whole  assay.  This  per  cent,  the  assayer  might  readily  cal- 
culate from  the  table,  thus:  Fe2  O3  is  the  ferric  oxide  found 
of  which  he  has  20  grains.  160  :  112  : :  100  :  x;  here  160 
is  the  theoretic  whole,  112  is  the  theoretic  iron  in  that  160 
parts.  Taking  160  as  the  100  per  cent,  or  the  actual 
whole,  x  is  the  per  cent,  iron  sought.  Multiply  the  second  and 
third  terms  of  the  proportion,  112  x  100  —  11,200,  and  divide 
by  the  first  term  160  and  we  have  70  as  the  per  cent,  sought. 
So  that  Fe2  O3  always  has  70  per  cent.  iron.  If  70  per  cent, 
is  iron,  then  30  per  cent,  must  be  oxygen.  Let  us  test  this 
latter  element  merely  to  prove  the  first.  Then  160  :  48  : : 
100  :  y  =  30 ;  now  as  70  +  30  =  100  the  proportion  is  proved, 
70  p.  c.  iron  +  30  p.  c.  oxygen  —  100.  Let  us  now  take  a 
very  complicated  illustration.  Thus,  suppose  the  compound 
found  is  a  hydrous  ammonium  salt  of  magnesia,  which  has 
been  precipitated  when  we  wish  to  find  phosphoric  acid,  or 


TABLE   OF   ATOMIC   WEIGHTS.  41 

phosphorus  in  an  iron  ore,  as  described  hereafter  under  Iron. 
The  precipitate  is  composed  of  NH4MgPO2  +  6H2O,  and  is 
ammonium  magnesium  phosphate,  a  white  crystalline  pow- 
der. When  obtained  it  is  heated  to  redness  to  drive  off  all 
the  volatile  parts,  which  are  ammonia  and  water,  and  the 
changed  remaining  salt  is  weighed  as  2MgO,P2O5,  from 
which  we  wish  to  get  the  P  and  the  Mg.  We  will  suppose 
we  have  found  20  grains,  and  the  P  and  Mg  are  to  be  found 
from  2MgO,P2O5.  MgO  is  24+ 16  =  40,  2MgO  is  therefore 
40  x  2  =  80 ;  P2  is  31  x  2  =  62 ;  and  O5  is  16  x  5  =  80  ; 
62  +  80  =  142.  The  whole,  therefore,  is  80  +  142  =  222. 
222  :  62  : :  100  :  27.92  phosphorus.  Of  Mg  the  proportion 
to  the  whole  is  80  to  222,  or  36.04  per  cent.,  for  222  :  80  : : 
]  00  :  36.04.  Of  P2O5,  or  phosphoric  acid,  222  :  142  : :  100  : 
63.96 ;  that  is,  the  per  cent,  of  phosphoric  acid  is  63.96. 
Now,  as  20  grains  were  found,  of  which  27.92  per  cent,  is  P, 
20  x  27.92  —  5.58  grains,  these  are  P.  From  these  exam- 
ples the  student  may  understand  how  to  find  the  weight  of 
any  salt  or  compound.  It  would  be  well  for  the  assayer  to 
make  a  table  of  per  cent,  for  the  chief  elements  in  which  he 
is  interested  and  keep  it  before  him.  Having  the  per  cent, 
he  has  only  to  multiply  his  found  weight  by  the  per  cent,  to 
get  the  weight  of  the  element  sought.  Thus,  as  we  shall 
hereafter  see,  we  frequently  have  Fe2O3  in  our  assays,  there- 
fore note  that  this  means  70  per  cent,  iron  (Fe)  and  30 
oxygen.  So  treat  all  formulas  we  usually  obtain.  If  we 
get  say  20  grains  of  Fe2O3,  20  x  .70=14.00  grains  Fe.  And 
so  use  the  per  cent,  of  P  and  Mg,  when  we  get  2MgO,P2O5, 
and  any  other  precipitate  usually  formed  in  course  of  work 


42  MINERALS,    MINES,    AND   MINING. 

hereafter.     Form  a  table    and  use  it  without   calculation 
afterward. 

THE  GROUPS. 

The  groupings  of  compounds  may  form  very  convenient 
classifications,  which  it  is  well  for  the  student  to  study  in 
their  relations  to  the  action  of  reagents. 

FIRST  GROUP. — Metallic  oxides  not  precipitated  from  their 
solutions  by  sulphuretted  hydrogen,  hydrosulphuret  of  am- 
monia, or  alkaline  carbonates.  These  are  the  alkalies 
proper :  Potassa,  soda,  lithia,  ammonia. 

SECOND  GROUP. — Metallic  oxides  not  precipitated  from 
their  solutions  by  sulphuretted  hydrogen,  but  precipitated 
by  hydrosulphuret  of  ammonia  only  under  certain  circum- 
stances, as  salts,  and  also  precipitated  by  alkaline  carbon- 
ates. These  are  the  alkaline  earths :  Baryta,  strontia,  lime, 
magnesia. 

THIRD  GROUP. — Metallic  oxides  not  precipitated  by  sul- 
phuretted hydrogen,  but  precipitated  as  oxides  by  hydrosul- 
phuret of  ammonia.  Alumina,  glucina,  chromium  oxide, 
thorina,  yttria,  oxides  of  cerium,  zirconia,  titanic  acid,  tan- 
talic  acid. 

FOURTH  GROUP. — Metallic  oxides  not  precipitated  from 
their  acid  solutions  by  sulphuretted  hydrogen,  but  com- 
pletely precipitated  by  hydrosulphuret  of  ammonia  as  sul- 
phurets.  Oxide  of  zinc,  oxide  of  nickel,  oxide  of  cobalt, 
protoxide  of  manganese,  protoxide  and  sesquioxide  of  iron, 
and  sesquioxide  of  uranium. 

FIFTH   GROUP.— Metallic  oxides    completely  precipitated 


THE   REAGENTS.  43 

from  their  solutions,  whether  acid,  alkaline,  or  neutral,  by 
sulphuretted  hydrogen,  their  sulphurets  being  insoluble  in 
alkaline  hydrosulphurets.  Oxide  of  lead,  oxide  of  silver, 
oxides  of  mercury,  oxide  of  bismuth,  oxide  of  cadmium, 
oxide  of  copper,  oxide  of  palladium,  sesquioxide  of  rhodium, 
oxide  of  osmium. 

SIXTH  GROUP. — Metallic  oxides  completely  precipitated 
from  their  acid  solutions  by  sulphuretted  hydrogen,  but  not 
from  their  alkaline  solutions,  their  sulphurets  being  soluble 
in  alkaline  sulphurets.  Oxide  of  antimony,  oxide  of  arsenic, 
oxide  of  tin,  oxide  of  platinum,  oxide  of  iridium,  oxide  of 
gold,  oxides  of  selenium,  tellurium,  tungsten,  vanadium,  and 
molybdenum. 

As  the  student  proceeds  he  may  readily  derive  great  help 
from  the  study  of  the  preceding  characteristics  of  metallic 
oxides,  and  we  shall  have  reason  to  refer  some  oxides  to 
these  groups  when  speaking  of  the  effect  of  certain  reagents 
upon  them. 

THE  REAGENTS. 

WATER. — Formula  H2O.  Atomic  weight  18.  Only  the 
purest  water  should  be  used  for  the  finest  analyses.  Rain 
water  falling  from  a  metallic  roof,  or  from  a  shingle  or  slate 
roof,  after  it  has  been  thoroughly  washed,  may  be  used  under 
precautions:  1st,  that  it  is  not  near  the  sea-shore;  impurity, 
sea  salt,  tested  by  silver  nitrate ;  2d,  that  it  has  no  organic 
matter  in  it,  this  impurity  interferes  by  keeping  some  salts 
in  solution  which  should  precipitate,  and  otherwise  tested  by 
adding  a  few  drops  of  pure  sulphuric  acid  to  the  water  in  a 


44  MINERALS,   MINES,    AND   MINING. 

medium-sized  test  tube,  then  add  a  solution  of  permanganate 
of  potassium,  and  gradually  heating  to  150°  F.,  if  this  dis- 
colors the  permanganate  then  it  contains  organic  matter; 
3d,  in  another  test  tube  of  the  water,  let  fall  a  drop  or  two 
of  hydrosulphide  of  ammonium — it  should  remain  a  clear 
straw  tint.  Any  other  appearance  indicates  some  metallic 
salt.  Distilled  water  is  the  best;  steam  from  an  engine 
may  contain  grease  or  oil.  Rain  water,  as  above  tested,  is 
next  to  distilled  water. 

ALCOHOL. — The  usual  alcohol  of  the  drug  store  is  85  per 
cent.,  and  is  used  in  chemical  work  both  for  burning  and 
for  assays.  Absolute  alcohol  is  generally  considered  free 
from  water,  but  this  is  seldom  quite  true,  and  it  is  seldom 
used.  Methylic  alcohol  is  cheaper  and  answers  well  for 
burning  and  blowpipe  purposes. 

HYDROGEN,  H,  atomic  weight  1.  It  may  be  prepared 
for  common  use  by  using  granulated  zinc  and  dilute  sul- 
phuric acid.  Add  about  one  part  acid  to  five  or  six  parts 
water,  and  pouring  slowly  upon  the  zinc  in  a  bottle  which 
will  bear  a  little  heat,  as  the  acid  gives  off  heat  when  the 
water  is  added  to  it.  Zinc  may  be  granulated  by  melting  it 
in  a  Hessian  crucible  and  pouring  it  from  a  little  height  into 
a  bucket  of  cold  water.  Hydrogen  is  sometimes  used  in 
reducing  finely  powdered  iron  ore  to  iron.  In  such  a  case 
it  should  be  dry,  and  to  obtain  it  thus  it  is  passed  through  a 
glass  tube  filled  with  chloride  of  calcium.  If  needed  very 
pure,  the  zinc  must  be  pure.  By  passing  it  through  a  solu- 
tion of  caustic  potash  it  may  be  rendered  purer,  and  Mallet 


THE   REAGENTS.  45 

recommends  additionally  the  passage  through  a  solution  of 
bichloride  of  mercury. 

If  a  small  quantity  is  needed,  absolutely  pure,  it  may  be 
collected  over  sodium,  or  by  the  galvanic  decomposition  of 
water  between  platinum  electrodes  as  in  the  usual  way  by 
using  a  battery. 

CHLORINE,  Cl,  35.5.  By  substracting  H  from  hydro- 
chloric acid  we  have  the  chlorine.  This  is  best  done  by 
treating  a  mixture  of  peroxide  of  manganese  to  hydrochloric 
acid  in  a  flask.  As  the  chlorine  is  exceedingly  disagreeable 
and  injurious  to  breathe,  the  acid  should  be  poured  into  the 
flask  through  a  safety-tube  bent  in  the  form  here  shown  at 
B.  The  manganese  and  acid  are  put  into  A,  the  latter  being 

Fig.  1. 


poured  into  E\  there  will  always  be  some  acid  at  B  prevent- 
ing any  chlorine  from  escaping.  The  chlorine  passes  over 
to  C,  and  if  the  water  in  the  bottle  C  is  cold  it  will  absorb 
rapidly,  but  if  driven  over  from  A  too  fast,  it  will  escape 
from  D.  When  saturated  pour  it  into  a  glass  stopped  bot- 
tle, put  it  in  a  cool  place  out  of  light,  and  generally  upside 
down,  since  in  that  position  the  gas  is  less  likely  to  escape. 


46  MINERALS,   MINES,    AND    MINING. 

The  covering  of  bottles  is  always  most  efficient  if  we  use 
thick  pasteboard  cylinders  of  just  sufficient  height  and 
diameter  to  slip  over  the  bottle  easily,  for  if  a  closet  is  used 
the  evaporations  from  various  solutions,  saturations,  and 
reagents  in  some  degree  combine  or  deposit,  and  may  create 
an  unpleasant  odor  and  injure  reagents,  and,  moreover,  every 
exposure  to  light  in  order  to  use  one  reagent  affects  all  the 
rest  within  the  closet,  and  it  is  no  more  trouble  to  remove 
the  cover  than  to  open  the  closet,  and  very  few  reagents  need 
be  kept  in  the  dark.  Black  bottles  are  inconvenient,  as  we 
cannot  tell  the  condition  of  the  reagent. 

Chlorine  may  sometimes  be  used  simply  as  a  gas.  Toward 
the  close  of  the  operation  it  will  be  well  to  heat  the  flask 
gently  by  the  spirit-lamp,  placing  the  latter  under  the  flask 
and  drawing  it  away  soon  to  prevent  too  sudden  heat,  then 
replacing  again ;  or,  better  yet,  place  a  close  wire  netting  on 
the  stand  (14  to  15,  or  more  wires  to  the  inch),  and  set  the 
flask  upon  that  before  applying  the  lamp.  It  would  be  well 
to  join  the  tubes  at  F  by  a  piece  of  rubber  tube ;  sheet  rub- 
ber is  a  poor  thing  to  keep  in  the  laboratory,  unless  kept  in 
a  tin  tube,  as  it  soon  becomes  weak,  but  when  new  it  may 
be  of  service.  Tie  (with  a  soft  cotton  thread)  your  connec- 
tions by  rubber  tube  or  rubber  sheet. 

BROMINE  AND  IODINE,  Br,  80  and  I,  127  (126.8). 

Both  of  these  are  used  as  deoxygenating  reagents.  As 
sold,  by  good  druggists  and  chemists,  they  are  generally  pure 
enough.  Br  must  be  kept  very  closely  in  well  stopped  bot- 
tles. It  is  used  in  three  forms:  (1)  as  free  bromine;  (2)  as 
a  bromine  water  which  holds,  at  ordinary  temperature,  about 


THE   REAGENTS.  47 

three  per  cent,  of  Br;  (3)  as  solution  in  hydrochloric  acid 
which  dissolves  about  twelve  per  cent. 

Sulphides  (as  iron  pyrites),  even  in  crystals,  are  readily 
decomposed  by  Br.  Sulphur  is  more  readily  oxidized  by  Br 
than  by  nitric  acid ;  and  precipitated  sulphides  are  thus  easily 
broken  up,  and  brought  to  a  state  fit  for  weighing,  without 
the  necessity  of  burning  the  filter  in  order  to  get  the  weight 
of  particles  often  so  entangled  in  the  filter  that  burning 
becomes  necessary,  as  we  shall  see  in  some  processes  here- 
after described.  The  presence  of  ammoniacal  salts  (with 
which  Br  liberates  nitrogen)  hinders  the  formation  of  per- 
oxides in  acid  solutions  of  cobalt,  nickel,  and  manganese, 
but  does  not  interfere  with  that  in  the  like  solutions  of  iron, 
tin,  and  mercury  (Mallet  and  Fresenius).  It  is  superior,  in 
some  respects,  to  chlorine  water  as  an  oxidant.  Mallet 
finds  that  Br  and  iodine  together  act  more  energetically  in 
breaking  up  cast-iron,  for  liberation  of  its  carbon,  than  either 
alone ;  and  Br,  through  which  chlorine  has  been  passed,  acts 
more  rapidly  than  that  element  alone. 

Br  is  bought  in  liquid  form,  and  of  very  dark  brown,  and 
iodine  in  tabular  flakes,  somewhat  crystalline.  The  fumes 
of  Br  should  be  avoided,  although  very  slight  inhalations  of 
either  I  or  Br  are  not  necessarily  injurious.  Stains  upon  the 
hands  disappear  after  a  while. 

Bromine  may  be  prepared  by  mixing  the  crystals  of  bro- 
mide of  potassium  with  peroxide  of  manganese,  and  diluted 
sulphuric  acid,  three-quarters  water,  the  former  two  in  about 
equal  parts,  and  adding  the  dilute  acid  so  as  to  cover  the 
mass  in  the  retort,  fastening  in  tightly,  by  clay  luting,  a  glass 


48  MINERALS,   MINES,   AND   MINING. 

tube  which  is  wrapped  and  kept  wet  with  very  cold  water, 
better  with  ice,  and  thus  the  vapors  condense  into  bromine 
liquid  in  an  ice-cold  receiver.  Very  gentle  heat  may  be 
applied  if  the  Br  is  slow  in  passing. 

OXYGEN,  O,  16.  Oxygen  is  obtained  by  various'processes, 
but  the  neatest  is  by  heating  chlorate  of  potassium  with  iron 
carbonate — the  cheap  so-called  drop  carbonate  of  iron  is 
quite  good  enough.  Usually,  peroxide  of  manganese,  the 
u  black  oxide,"  is  recommended,  which  is  good,  but  much 
more  uncleanly  and  harder  to  wash  out  in  cleaning  the 
retort.  With  the  carbonate  of  iron  the  escape  of  gas  may 
be  regulated,  or  even  entirely  arrested,  by  withdrawing  the 
lamp,  and  the  remaining  chlorate  be  used  again.  The  per- 
oxide of  manganese  and  the  iron  carbonate  are  not  decom- 
posed, but  simply,  by  their  presence,  they  facilitate  the 
decomposition  of  the  chlorate.  If  the  oxygen  is  to  be 
extremely  pure,  chlorine  traces  must  be  eliminated  after 
manganese  peroxide  is  used,  or  carbonic  anhydride  (CO2) 
after  the  carbonate  of  iron,  but  it  is  rarely  that  the  oxygen  is 
not  sufficiently  pure  with  either.  The  little  sparkling  which 
sometimes  occurs  in  the  retort,  due  to  some  small  organic 
matter,  is  of  no  injurious  consequence  in  any  way  unless 
very  dirty  material  is  used  in  the  peroxide. 

IRON,  Fe,  56.  This  is  sometimes  used  for  standardizing 
for  volumetric  analyses.  The  purest  iron  is  generally  ob- 
tained in  piano  wire.  It  is  said  to  contain  only  four  one- 
thousandths  of  impurity,  and  is  consequently  -f^fa  pure  iron. 
But  this  is  not  always  so,  and  the  wire  must,  for  volumetric 
analysis,  be  analyzed,  and  the  amount  of  pure  iron  deter- 


THE    REAGENTS.  49 

mined,  and  allowance  made  for  it.  After  a  wire  has  been 
analyzed  in  part,  the  remaining  part  may  be  considered  to 
be  the  same  in  purity  as  the  section  analyzed.  It  may  then 
be  kept  in  short  pieces  in  a  bottle  free  from  dust  and  rust, 
being  marked  as  to  fineness. 

ZINC,  Zn,  65.  This  is  used  in  various  operations,  besides 
simply  for  hydrogen.  In  volumetric  analysis  we  require 
that  it  should  be  pure,  and  it  can  be  distilled  into  water  from 
an  iron  crucible  with  iron  cover  and  tube  fitted.  It  can  be 
had  from  the  chemical  ware-stores  in  thin  plates  an  eighth 
of  an  inch  thick,  nearly,  if  not  quite,  chemically  pure. 

TIN,  Sn,  118.  This  is  used  by  some  in  thin  slips  for 
determination  of  phosphorus  and  for  the  preparation  of 
chloride  of  tin.  The  grain  tin  of  commerce  may  be  em- 
ployed. 

HYDROCHLORIC  ACID,  HC1,  36.5.  Pure  acid  is  colorless. 
Color  indicates  free  chlorine,  or  ferric  chloride,  and  the  test 
is,  that  it  turns  blue  immediately  on  the  addition  of  a  little 
paste  of  starch  and  iodide  of  potassium.  Test  it  for  the 
presence  of  sulphuric  acid  by  diluting  it  twice  or  thrice  its 
volume  with  water,  and  adding  three  or  four  drops  of  chlo- 
ride of  barium ;  a  cloudy  appearance  indicates  its  presence. 
But  the  ordinary  shop  hydrochloric  acid  is  also  used,  espe- 
cially in  making  chlorine  and  for  other  purposes,  and  when 
the  only  impurity  present  is  chlorine,  it  is  good  for  gold 
solution  and  for  the  precipitation  of  silver.  The  presence 
of  iron  may  be  proved  by  the  precipitation  of  the  peroxide 
of  iron  on  addition  of  ammonia  to  a  diluted  small  amount  of 
the  acid ;  till  the  ammonia  can  plainly  be  smelled,  let  it 


50  MINERALS,   MINES,    AND   MINING. 

stand,  and  if  no  brown  precipitate  occurs  after  gentle  heat 
and  rest,  iron  is  either  entirely  absent  or  extremely  small  in 
amount. 

NITRIC  ACID,  HNO3,  63.  This  is  employed  in  two  con- 
ditions, concentrated  nitric  acid,  usually  colored,  and  ordi- 
nary nitric  acid  which  is  less  concentrated,  and,  when  pure, 
colorless.  It  ought  not  to  show  presence  of  sulphuric  acid 
(the  test  is  the  same  as  in  hydrochloric  acid),  and  it  also  should 
have  no  free  chlorine ;  it  may  be  tested  by  nitrate  of  silver, 
a  drop  of  which  will  cause  a  white  cloudy  precipitate  of 
chloride  of  silver,  dense  in  proportion  to  the  amount  of 
chlorine  present. 

AQUA  REGIA. — This  is  the  name  given  to  a  mixture  of 
nitric  and  hydrochloric  acids,  one  volume  of  the  former  to 
three  or  four  of  the  latter.  It  is  better  to  make  this  when 
you  use  it  for  dissolving  gold. 

SULPHURIC  ACID,  H2SO4,  98.  When  pure  it  is  colorless. 
The  presence  of  any  organic  matter,  a  piece  of  cork,  straw, 
etc.,  for  instance,  will  darken  the  whole.  Hence,  no  corks 
should  be  used.  It  has  little  effect  upon  beeswax  stoppers, 
but  glass  stoppers  are  to  be  preferred.  A  current  of  hydro- 
sulphuric  acid  (sulphuretted  hydrogen)  should  produce  no 
precipitate  in  the  pure  dilute  acid.  When  diluted  with 
twice  or  thrice  its  volume  of  water,  it  should  not  decolor  a 
drop  of  a  solution  of  permanganate  of  potassium  let  fall 
into  it,  either  immediately,  due  to  the  presence  of  SO2,  or 
after  long  contact  with  a  slip  of  pure  zinc,  due  to  the  presence 
of  nitric  acid.  Arsenic,  if  present,  is  indicated  in  its  pre- 
cipitation by  sulphide  of  barium,  which  brings  down  the 


THE   REAGENTS.  51 

arsenic,  and  any  excess  of  sulphide  is  converted  into  insolu- 
ble sulphate,  and  this  latter  method  may  be  used  for  puri- 
fying H2SO4  from  this  element  (Dupasquier}. 

HYDROSULPHURIC  ACID  GAS,  or  sulphuretted  hydrogen,  or 
dihydric  sulphide,  H2S,  34.  This  is  formed  by  the  action  of 
sulphuric  acid,  or  dilute  hydrochloric  acid,  on  sulphide  of 
iron.  Hydrochloric  acid  is  preferable,  since  sulphuric  acid 
crystallizes  with  the  iron  too  easily.  The  apparatus  shown 
in  the  section  upon  chlorine  may  be  used.  Into  the  flask 
put  some  small  pieces  of  sulphide  of  iron  and  pour  upon 
them  diluted  H2SO4  or  HC1 ;  convey  the  gas  into  some  water 
(a  wash-bottle)  to  collect  any  impurities  which  may  come 
over,  and  by  means  of  another  tube  bent  down,  it  may  be 
conveyed  into  an  assay  solution  when  we  wish  it  to  be  satu- 
rated. For  this  purpose  we  may  cheaply  buy  the  sulphide 
of  iron,  or  by  heating  a  bar  of  iron  white  hot  in  a  black- 
smith's fire  and  pressing  it  against  a  roll  of  brimstone,  the 
iron  combines  and  drops  off  as  sulphide  and  may  be  caught 
in  water.  Or  a  mixture  of  three  parts  of  iron  filings  with 
two  parts  of  flowers  of  sulphur  projected  into  a  Hessian 
crucible  heated  red  hot,  covered  until  well  melted,  and  then 
the  contents  poured  out  upon  an  iron  plate,  or  a  stone  sur- 
face, will  supply  all  the  sulphide  needed.  After  using  the 
apparatus,  wash  all  out,  and  the  remains  of  sulphide  of  iron 
may  be  kept  in  the  flask  for  the  next  time.  As  there  is  no 
need  to  heat  the  bottle,  any  glass  bottle,  with  a  wide  mouth 
for  fitting  in  the  cork  and  tubes,  may  be  used,  and  kept  for 
that  purpose  only,  thus  releasing  the  flask  for  more  im- 
portant service. 


52  MINERALS,   MINES,   AND   MINING. 

ACETIC  ACID,  C2H4O2,  60.  The  usual  acetic  acid  of  com- 
merce, containing  about  thirty  per  cent,  of  normal  acid,  is 
generally  used.  It  is  pure  enough  when  it  leaves  no  resid- 
uum upon  evaporation  from  a  platinum  slip. 

OXALIC  ACID,  C2H2O4  +  2H2O,  126.  This  acid  is  used  to 
standardize  solutions  of  permanganate  of  potassium.  It  is 
pure  when  no  residuum  is  left  upon  a  strip  of  platinum  foil. 
But  if  not  pure,  it  must  be  re-crystallized  by  nearly  dissolv- 
ing a  mass  of  crystals  in  hot  water  in  a  porcelain  basin,  and 
when  no  more  crystals  will  dissolve  pouring  all  the  solution 
upon  a  filter  paper  and  filter  into  another  basin  and  set  by, 
in  a  warm  place,  to  crystallize.  The  mother  liquor  is  poured 
off  from  the  crystals  and  returned  to  the  former  mass,  and 
the  crystals  drained  and  laid  on  filter  paper  to  dry,  and  then 
bottled  in  a  wide-mouth  bottle  for  use.  Test  some  of  it  upon 
a  clean  piece  of  platinum  foil.  More  crystals  can  be  formed 
from  the  remaining  solution  until  the  mother  liquor  becomes 
of  little  quantity,  and  then  it  is  generally  seen  to  be  impure, 
and  should  be  thrown  away.  By  use  of  this  salt  and  car- 
bonate of  ammonium,  and  by  crystallization,  the  assayer 
may  make  chemically  pure  oxalate  of  ammonium,  as  a 
reagent,  for  separating  lime  in  his  assays. 

SUCCINIC  ACID,  C4H6O4,  118.  This  acid  is  preserved  in 
colorless  crystals,  and  is  used  in  making  the  reagent  suc- 
cinate  of  ammonium.  It  should  not  leave  any  residuum 
upon  platinum  foil. 

TARTARIC  ACID,  C4H6O6,  150.  A  solution  of  this  acid  in 
water  is  apt  to  mould,  but  it  is  said  that  if  a  small  lump  of 
camphor  (gum)  is  dropped  into  the  bottle  it  will  remain 


THE   REAGENTS.  53 

without  mould.  Mallet  says  that  if  the  solution  is  made 
with  boiling  pure  water,  and  the  solution  decanted,  without 
filtering,  into  the  bottle,  it  will  keep  a  long  time. 

SULPHUROUS  ACID  or  ANHYDRIDE,  SO2,  64.  This  is  pre- 
pared by  the  action  of  sulphuric  acid  upon  metallic  copper. 
The  apparatus  is  the  same  as  for  chlorine  (see  Chlorine), 
except  that  a  strong  heat  is  applied  under  the  flask  or  retort. 
Pour  into  the  flask,  or  retort,  four  parts  sulphuric  acid  to  one 
of  copper  strips,  or  wire,  and  apply  heat — better  with  a  wire 
gauze  or  netting  under  the  flask — heat  gradually  at  first  and 
cautiously  to  prevent  bubbling  over.  Pass  the  gas  into  the 
assay  solution  intended  to  be  saturated,  or,  if  intended  for 
keeping  in  solution,  pass  it  into  stoppered  bottles  with  cold 
distilled  water,  cork  up  tightly  and  remove  to  a  cool  dark 
place. 

CARBONIC  DIOXIDE,  or  carbonic  acid  gas,  CO2,  44.  This  is 
easily  made  by  the  action  of  hydrochloric  acid  upon  pieces 
of  marble ;  the  acid  seizes  upon  the  lime  of  the  lime  car- 
bonate and  the  CO2  is  set  free,  thus  CaCO3  +  2HC1  =  CaCl2 
+  H20  +  CO2. 

MOLYBDIC  ACID,  MoO3,  144.  This  is  used  in  the  prepara- 
tion of  molybdate  of  ammonium.  As  sold,  it  is  sufficiently 
pure. 

POTASSA,  KHO,  56.  Pure  caustic  potass  is  sold  in  sticks. 
There  is  a  caustic  potass  which  cannot  be  used  because  of 
its  impurities;  it  is  called  a  lime  potass.  The  so-called  pure 
stick  potass  frequently  contains  some  silica  and  perhaps  a 
little  lime  and  iron  from  which  it  should  be  free.  It  is  best 
to  test  it  and  determine  from  a  known  weight  just  the  per 


54  MINERALS,   MINES,   AND    MINING. 

cent,  of  these  impurities  it  possesses,  and  then  in  assaying  to 
allow  for  the  amount  found.  It  should  be  kept  from  the 
air,  or  it  will  absorb  both  moisture  and  CO2.  It  may  be 
tested  as  follows :  a  watery  solution  of  KHO  neutralized  by 
hydrochloric  acid  should  not  be  affected  by  hydrosulphide  of 
ammonium,  nor  a  precipitate  be  formed  by  oxalate  of  am- 
monium. 

SODA,  NaHO,  40.  What  has  been  said  of  potass  equally 
applies  in  this  case. 

AMMONIA,  NH3,  17.  Used  as  ammonia  water,  which  is  a 
solution  of  the  gas,  should  be  colorless,  and  should  evapo- 
rate from  the  platinum  foil  without  leaving  a  stain.  It  may 
be  prepared  by  passing  the  gas  over  into  a  receiver,  the  lat- 
ter in  a  freezing  mixture.  The  gas  is  obtained  from  sal 
ammoniac,  crude  muriate  of  ammonium  of  commerce,  when 
heated  in  company  with  lime  powder,  and  it  may  be  made 
of  very  great  strength  if  the  solution  of  the  water  be  very 
cold  and  the  gas  be  passed  over  for  a  long  time.  It  should 
be  free  from  CO2;  the  test  is  lime  water;  this  should  present 
no  cloudiness.  But  it  should  be  kept  in  small  bottles,  as  it 
absorbs  CO2  from  the  atmosphere. 

LIME-WATER,  solution  of  calcium  hydrate,  CaO  +  H2O,  is 
obtained  by  digesting  slacked  lime  with  cold  water  in  excess, 
and  decanting  the  clear  water  from  over  the  lime.  It  must 
be  kept  from  the  air,  or  a  pellicle  of  lime  carbonate  will 
form  on  the  surface  and  become  troublesome. 

ALUMINA,  A12O3,  105.  This  is  employed  in  fluxes  for  the 
dry  method.  Good  common  clay  is  used  as  sufficiently  pure. 

LITHARGE,  PbO,  223.     Pure  litharge  may  be  known  by 


THE    REAGENTS.  55 

its  freedom  from  reddish  spots  of  red  lead  (Pb3O4),  and  also 
from  any  particles  of  lead.  Passing  it  through  a  sieve  will 
free  it  from  the  latter.  It  is  used  only  in  dry  assay. 

OXIDE  OF  COPPER,  CuO,  79.  The  black,  or  peroxide  of 
copper,  is  used  either  in  powder,  or  finely  granular  state,  the 
latter  when  used  for  making  oxygen  from  chlorate  of  potas- 
sium in  place  of  black  oxide  of  manganese,  or  iron  carbonate 
(see  Oxygen).  It  is  also  used  in  the  quantitative  analysis  of 
iron  to  determine  the  carbon  by  its  combustion  into  CO.2. 

NITRATE  OF  POTASSIUM,  KNO3,  101.  The  nitre  of  com- 
merce, by  one  or  two  crystallizations,  becomes  pure  enough 
for  usual  purposes. 

SULPHATE  OF  POTASSIUM,  KHSO4,  136.  If  pure,  hydro- 
sulphide  of  ammonium  should  occasion  no  precipitate  which 
would  indicate  the  presence  of  alumina,  or  some  metallic 
salts. 

CARBONATE  OF  POTASSIUM,  K2CO3  -f  2H2O,  174.  The 
solution  of  this  salt  in  pure  water  should  be  perfectly  clear, 
and,  when  neutralized  by  hydrochloric  acid,  should  give  no 
precipitate  and  none  with  chloride  of  barium,  showing 
absence  of  sulphates,  and  also  none  with  hydrosulphide  of 
ammonium,  showing  absence  of  metallic  salts  and  of  alumina. 
The  solution  evaporated  to  dryness  in  a  capsule  should  leave 
nothing  insoluble,  showing  absence  of  silica  and  other  ele- 
ments. But  for  some  assays  (dry)  potassium  carbonate  need 
not  be  required  of  such  purity,  as  in  the  making  of  black  flux. 

BLACK  FLUX. — This  is  a  mixture  of  the  last-mentioned 
salt  and  finely  divided  charcoal.  It  is  made  by  mixing  one 
part  of  saltpetre  and  two  parts  of  crude  tartar  (acid  tartrate 


56  MINERALS,    MINES,   AND   MINING. 

of  potassium)  or  argol,  which,  when  purified,  is  so-called 
cream  of  tartar.  This  mixture  is  put  into  an  iron  vessel  or 
pot,  and  set  fire  to  by  a  piece  of  lighted  charcoal  and  when 
burned  out  is  broken  up  and  put  into  a  box  in  a  dry  place. 

CHLORATE  OF  POTASSIUM,  KC1O3,  122.5.  It  is  sufficiently 
pure  as  sold  in  the  drug-stores,  and  may  be  proved  as  the 
nitrate  is,  or,  if  not  pure,  recrystallized.  (See  under  Oxygen.) 

PERMANGANATE  OF  POTASSIUM,  K2Mri2Os,  316.     Furnished 
sufficiently  pure  in  the  crystals  to  be  had  at  the  chemical 
shops.     Generally  the   larger  crystals  are  the  purest.     It 
may  very  easily  be  formed  by  the  following  process :    Take 
4  parts  finely  powdered  black  oxide  of  manganese  (or  a 
purer  form  of  peroxide,  which  is  also  the  binoxide),  inti- 
mately mix  it  with  4|  parts  of  chlorate  of  potassium  and  5 
parts  of  hydrate  of  potass  dissolved  in  a  very  little  water. 
The  pasty  mass  is  dried,  and  heated  to  dull   redness  for 
some  time  (half  hour)  in  an  iron  pot  or  clay  crucible.     The 
oxygen  derived  from  the  chlorate  of  potassium  converts  the 
binoxide  of  manganese  into  manganic  acid,  which  combines 
with  the  potash  of  the  hydrate.     On  treating  the  whole  mass 
with  water,  the  manganate  of  potash  is  dissolved,  forming  a 
dark  green  solution.     This  is  diluted  with  water,  and  a  stream 
of  carbonic  dioxide  (CO2)  passed  through  it  as  long  as  any 
change  of  color  is  observed;  the  CO2  combines  with  the 
excess  of  potash,  the  presence  of  which  conferred  stability 
upon  the  manganate,  which  is  then  decomposed  into  per- 
manganate of  potash  and  binoxide  of  manganese.    The  latter 
is  allowed  to  settle,  and  the  clear  red  solution  poured  off 
and  evaporated  to   a  small  bulk.     On  cooling,  it  deposits 


THE   REAGENTS.  57 

prismatic  crystals  of  the  permanganate  of  potash,  which  are 
red  by  transmitted  light,  but  reflect  a  dark  green  color. 
Draw  out  the  crystals  and  dry  upon  a  porous  tile. 

Permanganate  of  potassium  has  great  coloring  power,  and 
the  readiness  with  which  it  loses  this  color  in  the  presence 
of  organic  matter  gives  it  great  importance.  Sulphurous 
acid,  or  a  ferrous  salt,  deprives  it  of  its  color,  and  hence  this 
property  is  utilized  in  the  volumetric  analysis  of  iron. 

SULPHOCYANIDE  OF  POTASSIUM,  KCNS,  97.  Is  only  made 
use  of  in  the  quantitative  determination  of  the  persalt  of  iron. 
One  part  of  the  salt  to  10  or  15  of  water  is  the  proper 
strength  of  solution.  (See  Volumetric  Analysis.) 

CHLORIDE  OF  SODIUM,  NaCl,  58.5.  It  should  be  free  from 
sulphates ;  the  test  is  barium  chloride.  Pure  table  salt,  dry, 
is  sufficiently  pure  for  most  experiments.  It  is  used  in  the 
quantitative  determination  of  sulphur  in  the  dry  way,  in 
order  to  reduce  the  intensity  of  the  action  of  the  saltpetre 
with  which  it  is  used. 

SULPHURET  OF  SODIUM,  or  sodium  sulphide.  Na2S  -f 
9H2O,  240.  The  usual  crystal  in  which  it  may  be  found  in 
the  shops  is  pure  enough.  It  is  used  in  the  volumetric 
determination  of  zinc.  It  should  be  kept  in  well-stopped 
bottles,  as  it  deliquesces.  A  solution  is  made  thus :  Make  a 
lixivium  of  pure  caustic  soda,  divide  it  into  two  equal  parts, 
through  one  of  which  pass  hydrosulphuric  acid  gas  to  satu- 
ration, then  reunite  both  parts,  adding,  if  necessary,  a  little 
solution  of  caustic  soda,  to  remove  completely  the  odor  of 
the  hydrosulphuric  acid,  and  then  filter  to  obtain  a  clear 
liquid. 


58  MINERALS,   MINES,    AND   MINING. 

SULPHITE  OF  SODIUM,  Na2SO3  +  1()H3O,  306.  The  solu- 
tion should  be  clear,  and  after  heating  with  sulphuric  acid 
to  expel  the  sulphurous  anhydride  it  should  not  be  affected 
by  hydrosulphide  of  ammonium. 

CARBONATE  OF  SODIUM,  Na2CO3  +  10H2O,  286.  It  is  to 
be  tested  as  in  the  case  of  carbonate  of  potassium,  with 
which  it  is  used  to  break  up  those  bodies  which  are  insoluble 
in  acids,  and  thereby  render  them  soluble.  The  two  mixed 
in  the  proportions  of  13  parts  carbonate  of  potassium  and 
10  parts  carbonate  of  sodium  are  found  more  efficient 
than  either  separately,  and  thus  it  is  called  "  sodic  carbonate 
of  potassium." 

BORAX,  ordinary  borax,  unheated,  is  a  biborate  of  sodium 
with  10  parts  of  water  of  crystallization.  This  water  may 
be  driven  out  with  advantage  to  the  operator  with  the  blow- 
pipe, and  then  it  is  called  the  "  glass  of  borax."  It  is  used 
as  a  flux  in  dry  assays.  It  is  sufficiently  pure  as  sold  in 
the  shops. 

PHOSPHATE  OF  SODIUM,  Na2HPO4  +  12H2O,  358.  One 
part  of  sodium  phosphate  in  ten  of  water  is  the  proper 
solution.  No  residue  should  be  left  in  the  solution,  if  the 
salt  is  pure,  and  no  effect  should  be  produced  by  ammonia 
even  when  the  solution  is  warm. 

ACETATE  OF  SODIUM,  C2NaH3O2,  136.  The  solution  should 
be  clear,  and  no  effect  should  follow  the  addition  of  oxalate, 
or  hydrosulphide,  of  ammonium. 

SUCCINATE  OF  SODIUM,  C4H4Na2O2  +  6H2O,  270.  This  is 
preferred  to  succinate  of  ammonium  only  because  it  is  easily 


THE   REAGENTS.  59 

had  in  commerce;  but  the  latter  leaves  no  insoluble  residue. 
Tests  are  the  same  as  for  the  acetate. 

NITRO-PRUSSIDE  OF  SODIUM,  FeNaa(CN)8NO  +  2H2O.  This 
is  only  used  in  qualitative  analysis.  It  may  readily  be  had 
at  the  chemical  stores.  It  is  valuable  with  the  blowpipe  for 
some  assays  of  sulphur  to  be  hereafter  mentioned. 

CHLORIDE  OF  AMMONIUM,  NH4C1,  53.5.  It  should  leave 
no  residue  on  platinum  foil.  It  should  be  colorless,  and 
give  no  precipitate  with  hydrosulphide  of  ammonium. 
Employ  five  parts  of  water  to  one  of  the  salt.  Sal  ammoniac 
of  commerce  (ammonium  muriate)  is  tolerably  pure,  except- 
ing a  little  iron  on  outside  pieces. 

HYDROSULPHIDE  OF  AMMONIUM,  (NHJHS,  51.  This  is 
obtained  by  supersaturating  aqua  ammonia  with  hydro- 
sulphuric  acid  gas.  It  is  also  best  to  have  a  solution  not 
quite  supersaturated,  and  both  should  be  kept  in  well-stopped 
bottles  away  from  both  heat  and  light.  Though  this  may- 
be had  in  the  stores,  it  is  better  to  make  it  in  the  laboratory, 
for  it  is  easily  made  of  the  strength  desired,  either  as  color- 
less or  yellow,  as  they  act  differently  according  to  amount  of 
sulphur.  (See  under  Zinc,  in  a  different  part.) 

MOLYBDATE  OF  AMMONIUM,  (NH4)2MoO4,  196.  This  re- 
agent is  employed  usually  in  solution  in  nitric  acid ;  one  part 
of  molybdic  acid  is  dissolved  in  eight  parts  of  aqua  ammonia 
and  twenty  parts  of  nitric  acid.  It  is  filtered.  It  is  used 
both  in  qualitative  and  quantitative  analyses. 

ACETATE  OF  AMMONIUM,  C2H3(NH4)O2,  77  (tested  as  in  the 
case  of  the  carbonate),  is  used  as  we  have  said  (acetate  of 
sodium)  in  the  place  of  the  sodium  acetate,  as  it  does  not 


60  MINERALS,   MINES,   AND   MINING. 

contain  fixed  matters,  but  it  is  a  little  more  expensive  for 
industrial  purposes. 

OXALATE  OF  AMMONIUM,  C2(NH4)2O4  +  H2O,  142.  One 
part  to  twenty-four  of  water.  May  be  tested  as  in  the  pre- 
vious ammonium  salts.  It  is  valuable  as  a  reagent  for  lime. 

NEUTRAL  SUCCINATE  OF  AMMONIUM,  C4H4(NH4)2O4,  152. 
The  commercial  crystallized  succinate  of  ammonium  is  the 
acid  succinate  C4H5(NH4)O4,  135,  but  the  neutral  is  pre- 
pared directly  from  the  succinic  acid  and  ammonia,  till  the 
solution  is  neutral,  as  tested  by  litmus  paper.  Or  it  may  be 
prepared  from  the  acid  succinate  above  mentioned  by  satu- 
rating with  ammonia  till  neutral. 

CHLORIDE  OF  BARIUM,  BaCl2  +  2H2O,  244.  Used  in  solu- 
tion with  ten  times  its  weight  of  water  should  be  completely 
soluble  and  show  no  precipitate  with  hydrosulphide  of  am- 
monium. 

NITRATE  OF  BARIUM,  BaN2O6,  261.  Make  the  solution  of 
fifteen  parts  water  to  one  of  the  salt.  Its  test  for  purity  is 
the  same  as  in  the  chloride. 

CARBONATE  OF  BARIUM,  BaCO3,  197.  This  is  made  in  the 
following  way:  Dissolve  chloride  of  barium  in  a  large  quan- 
tity of  warm  water,  heat  the  solution,  and  as  soon  as  it 
begins  to  boil,  pour  in  gradually  a  solution  of  carbonate  of 
ammonium  or  of  sodium,  until  precipitation  takes  place,  then 
let  the  fluid  settle,  protected  from  dust;  decant  the  clear 
fluid  and  repeat  the  washing  by  decantation  with  warm 
water  till  the  supernatant  fluid  gives  no  precipitation  with 
nitrate  of  silver.  The  carbonate  of  barium  should  remain 


THE   REAGENTS.  61 

suspended  in  as  much  water  as  will  form  a  cream,  and  be 
preserved  in  that  state  in  a  stoppered  bottle. 

CHLORIDE  OF  CALCIUM,  CaCl2,  111.  As  this  salt  is  used 
only  to  absorb  moisture  and  because  of  its  ready  deliques- 
cence, it  need  not  be  pure.  It  is  prepared  by  the  action  of 
hydrochloric  acid  upon  fragments  of  white  marble  until  the 
acid  is  saturated  with  the  marble,  and  then  the  solution 
evaporated  in  a  porcelain  dish  till  it  becomes  pasty,  porous, 
and  perfectly  dry.  In  the  latter  condition  it  is  better  than 
when  fused.  Break  it  up  into  fragments  and  preserve  it  in 
a  well-stopped  bottle,  remembering  that  it  absorbs  moisture 
rapidly  from  the  air. 

SULPHATE  OF  MAGNESIUM,  MgSO4  +  7H2O,  246.  This 
salt  is  used  to  precipitate  phosphoric  acid,  and  it  must,  when 
mixed  with  chloride  of  ammonium,  be  not  affected  either  by 
ammonia,  or  by  its  oxalate,  nor  by  hydrosulphide  of  ammo- 
nium, even  after  an  hour's  repose.  It  may  be  prepared  for 
use  thus:  Prepare  a  solution  of  one  part  of  crystallized  sul- 
phate of  magnesium  and  one  part  of  chloride  of  ammonium 
in  eight  parts  of  water ;  add  four  parts  of  ammonia,  let  it 
rest  for  some  days  and  then  filter.  The  common  name  for 
sulphate  of  magnesium  is  Epsom  salt. 

NITRATE  OF  SILVER,  AgNO3,  170.  The  usual  commercial 
salt  in  clear  crystals  is  usually  pure  enough.  One  part  to 
twenty  parts  of  pure  water  is  the  proper  dilution.  If  no 
organic  particles  exist  in  the  solution,  it  may  be  kept  in  the 
light  without  any  loss  of  clearness.  Dust  settling  around 
the  stopper  may  cause  some  degree  of  blackening,  but  it  is 
generally  a  matter  of  little  consequence,  and  occasional  care 


62  MINERALS,   MINES,    AND   MINING. 

in  dropping  will  prevent  any  important  results  from  exposure 
to  light.  (See  further  reference  to  this  salt  at  the  close  of 
these  remarks  on  Reagents.) 

A  very  convenient  method  of  making  pure  nitrate  of  silver 
in  crystals  may  be  adopted  as  follows :  Take  a  silver  coin 
(25  cts.)  and  dissolve  completely  in  common  nitric  acid  (free 
from  chlorine);  a  little  dark  powder  may  remain,  this  is  gold; 
filter  and  the  gold  powder  may  be  reduced  under  blowpipe, 
or  mashed  against  a  piece  of  steel  or  smooth  iron  surface 
with  another  hard  surface,  and  the  metallic  gold  color  will 
appear.  Into  the  clear  solution  pour  slightly  diluted  hydro- 
chloric acid  or  sodium  chloride,  till  no  further  white  precipitate 
falls.  Drop  several  pieces  of  granulated  zinc  into  the  vessel, 
and,  if  acid  enough,  the  acid  will  immediately  act  upon  the 
zinc  and  hydrogen  will  be  set  free,  which,  uniting  with  the 
chlorine  of  the  silver  chloride,  will  soon  begin  to  leave  the 
silver  as  a  pure  metal,  changing  the  white  chloride  into  a 
dark  gray  mass  of  pure  silver  powder.  After  the  silver  has 
been  entirely  reduced  and  no  specks  of  white  chloride  re- 
main, the  zinc  may  be  removed,  if  not  already  dissolved,  and 
the  mass  of  spongy  silver  well  washed  by  decantation  from 
the  blue  copper  solution  of  the  coin  and  from  the  zinc  and 
chlorine  which  may  be  in  solution.  Pure  nitric  acid  may 
now  be  gently  poured  on  till  all  the  silver  is  dissolved.  It 
may  then  be  poured  into  an  evaporating  dish  and  gently 
heated  till  crystals  appear,  which  may  be  removed  and  dried 
after  cooling.  If  carefully  managed,  the  crystals  are  pure 
nitrate  of  silver  in  very  perfect  form. 


CAUTIONS   AND   SUGGESTIONS.  63 

LITMUS  PAPER. — Digest  one  part  of  commercial  litmus  in 
six  parts  of  water,  filter  the  deep  blue  liquid  and  divide  it 
into  two  equal  parts ;  into  one  drop  carefully  some  very 
dilute  sulphuric  acid  until  the  blue  color  just  begins  to  show 
a  tinge  of  red ;  unite  the  two  parts  in  a  sufficiently  large 
dish  and  dip  in  some  sheets  of  unsized  paper;  dry  the  sheets 
by  hanging  them  where  no  acid  vapors  can  reach  them-; 
when  dry  cut  them  into  strips  half  inch  wide  and  put  them 
into  a  wide-mouthed  bottle  closed  from  dust. 

RED  LITMUS  PAPER,  for  testing  alkaline  solutions,  may  be 
made  by  adding  some  drops  of  sulphuric  acid  to  the  blue 
solution  until  the  color  is  changed  to  pink,  then  dipping  the 
paper  into  this  reddened  solution  and  drying  and  cutting 
into  strips  as  in  the  former  case. 

SALT  OF  LEAD  PAPER.  This  paper  is  used  only  in  the 
volumetric  analysis  of  zinc  by  sulphide  of  sodium.  Glazed 
paper,  or  note  paper  dipped  in  a  solution  of  acetate  of  lead 
and  dried,  will  detect  the  presence  of  sulphides  in  solution. 

MICROCOSMIC  SALT,  or  salt  of  phosphorus,  (HNaNH4)PO4, 
if  in  crystals  +  8H2O.  Used  with  blowpipe.  Boil  6  parts 
of  sodium  phosphate  and  1  part  ammonium  chloride  in  2 
parts  water,  for  a  few  seconds,  then  cool  and  crystallize. 
Recrystallize  after  addition  of  some  aqua  ammonia. 

CAUTIONS  AND  SUGGESTIONS. 

In  selecting  a  room  for  a  laboratory,  especially  in  a  house 
used  for  other  purposes,  choose  an  upper  room  or  one  aside 
or  on  the  corner  of  the  house  with  a  north  window.  Have 


64  MINERALS,   MINES,   AND   MINING. 

the  light,  if  there  is  plenty  of  it,  on  only  one  side,  or  at  best- 
have  no  cross  lights,  except  in  a  large  room  where  cross 
lights  do  not  interfere  with  ready  examination  of  assays. 
Place  the  assay  table  near  the  light.  It  is  important  to  use 
front  or  side  lights  in  determining  shades  of  color  and 
precipitations.  North  windows  are  always  the  best  if  they 
can  be  had.  If  possible,  cut  off  one  small  room  for  the 
assay  balances  to  keep  them  from  dust  and  fumes  of  the 
laboratory. 

For  a  private  laboratory  a  sand-bath  may  be  made  by 
filling  a  sheet  iron  pan  made  two  or  three  inches  deep,  with 
clean  sand.  The  sand  may  be  washed  by  being  shaken,  or 
stirred,  in  a  bucket  of  water  till  the  water  comes  off  clean, 
then  drained  and  placed  in  the  pan  to  dry.  This  made  firm 
upon  the  stove,  if  it  has  a  flat  top,  will  serve  all  the  pur- 
poses. If  a  hood  can  be  placed  over  this  sand-bath  leading, 
by  a  sheet-iron  stove-pipe,  into  the  chimney,  it  will  be  very 
useful  in  carrying  off  vapors  of  all  kinds. 

An  assay  furnace  may  readily  be  made,  as  we  have 
suggested  elsewhere  (see  Iron,  Dry  Assay),  by  using  fire- 
bricks or  even  common  red  bricks ;  the  latter  burn  out  sooner ; 
but  where  the  former  cannot  be  had  the  latter  will  answer, 
placed  in  a  sheet  iron  cylinder.  It  may  be  arranged  for  a 
cupelling  furnace  at  the  same  time,  as  we  have  already 
mentioned,  but  we  give  the  plan  in  outline  here. 

The  diameter  of  the  sheet  iron  cylinder  should  be  at  least 
17  inches,  better  20,  with  a  bottom  s wagged  upon  it  tightly, 
the  top  open  and  fitted  with  a  flanged  heavy  sheet-iron 
cover  E  K  Place  this  cylinder  as  in  the  figure  where  it  is 


CAUTIONS   AND    SUGGESTIONS. 


65 


permanently  to  be,  and  upon  a  hearth  of  common  brick 
F  F  F.  Begin  by  laying  one  round  of  bricks  and  fitting 
them  in  tightly  leaving  an  opening  at  C  for  draft.  The 
next  point  will  be  the  grating,  which,  if  it  cannot  be  had  of 


Fie.  2. 


-r  f  rr 

!  _„_!.  J...j 

1 

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¥>    J         J 

D 

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^H 

...n  i  

A        A     A      | 

i             •           i    p' 
:           !         i    r 

H^c 

M 

F    i     F   i          F     j 

1 

sufficient  diameter  at  a  stove  store,  may  be  made  from  J 
inch  by  If  inch  wrought  iron,  cut  in  lengths  to  suit,  with 
1|  inch  between  bars.  If  wrought  iron  must  be  used  it 
should  be  heavy  to  keep  from  sagging  under  heat.  Better 
to  put  your  carpenter  to  work  to  make  a  pattern  of  that  size 
and  have  it  cast.  The  pattern  need  not  be  very  true  nor 
neatly  finished  for  this  work,  and  cast  iron  always  outlasts 
wrought  iron.  But  generally  a  grate  may  be  had  from  the 
stove  dealers  and  the  brick  work  accommodated  to  the  grate. 
A  wood  pattern  allows  you  to  renew  the  grate  whenever 
burned  out.  Continue  building  up  the  brick,  filling  up  the 
interstices  with  smaller  pieces,  and  perhaps  mortar  or 
cement,  until  A  A  A  is  reached ;  at  P  place  a  brick  projec- 
tion, for  a  muffle  to  rest  upon  as  described  under  iron,  silver, 
and  gold  assays,  having  previously  had  an  opening  at  the 

5 


66  MINERALS,    MINES,   AND   MINING. 

front,  both  in  the  sheet-iron  case  and  the  brick  lining.  The 
muffle  should  be  bought  before  and  the  hole  and  shelf  brick 
projection  fitted  to  the  muffle.  Proceed  in  raising  the  lining 
inside  the  curve,  leaving  a  neat  hole  for  the  pipe  Z>,  and 
door  B.  At  the  door  top  lay  a  flat  bar  from  one  side  to 
another  in  order  that  the  bricks  may  be  laid  over  the  open- 
ing, and  thus  finish  till  the  lower  edge  of  the  flange  is 
reached.  Let  all  stand  for  a  day  and  then  kindle  a  small 
fire  with  chips  and  let  the  stove  slowly  heat  until  all  is  dry. 
The  cover  E  E  E  should  be  laid  on  so  that  it  can  easily  be 
removed,  and  when  used  as  a  furnace  for  crucibles,  it 
can  be  taken  off  entirely  when  drawing  out  the  crucibles. 
An  important  matter  is  the  draft;  there  should  be  a  good 
draft,  and  a  plug  of  brick  fitted  at  A  to  close  the  stove  up 
when  the  muffle  is  not  used,  and  when  used  the  muffle 
should  be  put  in  only  when  the  fire  is  started  and  the  coal 
level  with  the  muffle  bottom,  then  other  coal  added  until  all 
the  muffle  is  covered.  If  the  case  is  about  17  in  diameter 
and  the  bricks  4  inches  (fire  brick)  wide,  unless  the  end 
edges  are  knocked  off  the  fire  pot,  or  inside  space,  will  be 
only  9  inches,  unless  the  brick  be  placed  flat  side  against 
the  iron  case  which  will  answer  very  well.  But  if  a  larger 
size  is  wanted  for  the  space  inside,  calculations  therefor  are 
easily  made.  We  have  had  one  furnace  20  inches  in  diam- 
eter with  common  brick  laid  on  edge  which  has  worn  with 
one  relining  for  over  a  year  in  good  order.  Anthracite  will 
cut  through  quicker  than  coke,  or  charcoal,  but  it  is  a  more 
lasting  fire  and  must  be  used  where  much  evaporation  is 


CAUTIONS   AND    SUGGESTIONS.  67 

carried  on  running  through  the  night,  otherwise  coke  may  be 
used,  or  even  soft  coal  (bituminous). 

As  for  analytical  scales  for  quantitative  analyses,  one  that 
turns  at  less  than  a  milligramme  is  sufficiently  delicate,  the 
advantage  in  sensitive  scales  being  that  labor,  time,  and 
money  are  saved  to  the  assay er,  for  if  his  scales  will  not 
allow  of  accurate  weighing  small  quantities,  he  must  take 
more  of  the  assay,  and  use  more  of  the  reagents,  and  take 
more  of  his  time.  The  more  delicate  the  weighing,  there- 
fore, the  less  quantity  of  assay  need  be  taken  to  arrive  at 
the  same  results  which  might  be  obtained  by  greater  trouble. 
Never  weigh  hot  articles  or  assays,  ascending  currents  always 
making  the  weighing  inaccurate.  If  your  scales  are  covered 
with  a  tight  case  and  in  a  dry  room,  nothing  need  be  put 
within  the  case  to  absorb  moisture,  but  if  you  suspect  any 
moisture  a  little  unslaked  lime  or  dry  chloride  of  calcium 
may  be  placed  in  a  saucer  or  cup  within  and  back  of  the 
scales  or  in  a  corner.  Never  handle  small  or  large  weights 
in  fine  scales  with  your  fingers,  use  the  nippers  or  weight 
tongs.  Filter  papers  may  be  burned  in  porcelain  crucibles 
as  well  as  in  the  platinum.  Cut  your  papers  to  the  size  of 
five  or  seven  inches  diameter,  having  a  circular  piece  of  tin 
as  a  constant  measure ;  take  two  pieces  of  one  size  and  let 
them  soak  in  pure  water  a  half  hour,  and  then  drain  them, 
and,  when  perfectly  dry,  roll  them  up,  or  cut  one  up,  so  that 
it  will  go  into  the  crucible,  and  then  burn  it  to  a  uniform 
white,  all  the  carbon  being  burned  out ;  let  the  crucible  cool 
perfectly,  then  weigh  and  note  this  weight ;  treat  the  other 
piece  in  the  same  way  and  weigh ;  if  they  are  very  nearly 


68  MINERALS,   MINES,   AND   MINING. 

the  same  in  weight,  take  the  average  weight  and  make 
record  of  it,  on  a  similar  piece  of  paper,  as  the  ash  weight 
of  that  particular  size  minus  the  weight  of  the  crucible  in 
which  you  must  heat  the  filter  paper.  Always  cool  and 
weigh  before  placing  the  filter  paper  in  to  burn ;  the  weight 
of  the  crucible  taken  from  the  weight  of  crucible  and  ash, 
gives  the  ash  weight  of  that  size  and  of  that  kind  of  filter 
paper.  By  this  means  we  can  calculate  the  weight  of  pre- 
cipitations which  have  been  left  in  too  fine  a  powder  to  be 
separated  from  the  paper  in  filtration. 

HOW  TO  USE  RE  A  GENTS  AND  GLASSWARE. 

In  testing  with  silver  nitrate  a  slovenly  assayer  will  use 
ten  or  fifteen  drops  upon  the  assay  in  a  test  tube,  when  two 
drops  are  sufficient.  Neatness  requires  but  one  drop  skill- 
fully squeezed  out  by  lifting  the  stopper  a  little  way  up,  then 
turning  the  bottle  over  and  gradually  pressing  in  the  stopper. 
So  it  is  with  all  reagents,  use  no  more  than  is  necessary.  By 
a  little  practice  you  may  always  drop  one  drop,  lift  the  stop- 
per to  let  the  reagent  fall  back,  then  push  your  stopper  in. 
Do  all  this  with  one  hand,  except  perhaps  to  draw  the  stop- 
per out  at  first.  Beside  the  economy  you  can  always  more 
quickly  judge  as  to  how  your  analysis  and  washing  when 
filtering  are  proceeding,  by  always  using  the  same  amount 
of  reagent.  Practise  on  one  drop.  Keep  all  things  cleanly. 
Using  reagents  "in  excess,"  means  that  in  using,  for  in- 
stance, an  alkali,  you  must  make  the  liquid  decidedly  alka- 
line when  it  was  previously  acid.  This  is  tested  by  either 
smell,  as  in  ammonia,  or  by  red  litmus  paper.  So,  also,  in 


HOW   TO   USE   REAGENTS   AND   GLASSWARE.  69 

using  an  acid  "  in  excess,"  only  in  such  case  it  is  in  the 
reverse,  using  the  blue  litmus  or  testing  by  absence  of  any 
smell. 

CAUTION. — Very  frequently  in  using  ammonia  and  some 
other  reagents,  the  inexperienced  operator  may  find  that  to 
the  smell  and  to  the  sight,  and  by  the  test,  an  assay  may 
seem  to  be  what  it  is  not,  because  attention  has  been  drawn 
only  to  the  surface,  when  by  stirring  the  solution  it  may  be 
found  that  only  the  surface  to  some  small  depth  has  been 
acted  upon.  Therefore,  before  decision  has  been  made,  stir 
well  the  solution,  mixing  the  top  and  bottom,  and  then  make 
your  inference  upon  the  whole. 

A  small  glass  rod,  one-quarter  of  an  inch  in  diameter,  is 
generally  sufficient  for  solutions;  but  a  tube  hermetically 
sealed  at  the  end,  or  both  ends,  is  stronger  than  a  solid  rod 
of  the  same  diameter.  A  platinum  wire  of  one-eighth  inch 
thickness,  or  smaller,  and  several  inches  long,  is  of  greater 
service,  especially  in  heated  alkaline  mixtures  or  solutions 
in  the  platinum  and  porcelain  crucibles,  but  such  a  short 
rod  is  not  fit  for  large  solutions. 

HEATING  GLASSWARE. — Some  begin  carelessly  as  to  heat, 
and  they  are  apt  to  continue,  to  their  great  discomfort,  loss, 
and  cost,  to  the  end.  Glassware  is  made,  or  intended,  to 
stand  heat,  but  it  does  not  always  answer  the  end  nor  the 
intentions  for  which  it  was  made.  In  the  hands  of  a  careful 
operator  it  seems  as  if  the  glass  becomes  annealed  after  use. 
At  any  rate  in  the  same  operating  room  one  operator  will 
break  by  heat,  as  well  as  by  carelessness  in  other  ways,  one- 
third  more  of  his  stock  than  his  neighbor.  In  beginning, 


70  MINERALS,    MINES,   AND   MINING. 

great  care  in  heating  and  using  brittle-ware  will,  as  a  habit 
and  "  way  of  doing  things,"  stick  to  the  man  as  sharply  and 
closely  as  the  other  habit,  and  time  will  be  gained  as  well  as 
cost  avoided. 

Flasks  and  beaker  glasses  containing  solutions  may  be 
heated  by  a  spirit  lamp  more  safely  by  avoiding  the  place- 
ment of  the  sharp  upper  end  of  the  flame  against  the  bottom 
of  the  vessel.  Push,  or  hold,  at  the  beginning,  the  lamp  so 
that  the  flame  is  cut  off  half  way,  and  then,  moving  the  flame 
around  the  bottom  for  a  few  seconds,  withdraw  a  second  or 
two,  and  then,  returning  the  lamp,  perform  the  heating  in 
the  same  way  for  a  minute  or  so,  according  to  the  bulk  of 
solution  to  be  heated,  taking  care  (especially  when  the  liquid 
gets  hot)  that  the  wick  of  the  lamp  does  not  touch  the  glass ; 
any  good  glassware  may  always  allow  the  boiling  of  the 
solutions  without  any  danger  of  cracking  even  in  the  coldest 
room,  if  treated  in  this  way.  Some  glassware  breaks  more 
readily  than  others.  Preserve  that  glass  flask  or  beaker 
which  has  stood  the  heat  for  more  important  assays,  and  test 
your  new  flasks,  etc.,  with  water  (required  to  be  used  boiling) 
or  with  some  other  work  which,  in  case  of  the  fracture  of 
the  glass,  will  occasion  no  loss  worth  regretting. 

WATER  pure  enough  for  usual  work  may  be  caught,  as  we 
have  already  said,  from  a  roof  which  has  been  cleansed  by 
sufficient  rain.  If  not  near  the  seashore,  this  may  answer 
well  as  it  is,  but  it  may  contain  a  little  free  carbonic  dioxide 
(CO2),  which  however  is  extremely  small,  and,  after  consider- 
able rainfall,  entirely  unimportant.  The  water  may  be  kept 
in  a  glass  or  sheet  copper  vessel  with  a  cover  for  general 


LIST   OF   USUAL   CHEMICAL   APPARATUS.  71 

supply.  But  a  small  copper  box  with  a  pipe  leading  from 
the  top  long  enough  to  enter  a  receiver,  which  may  be  kept 
cold  summer  or  winter,  will  furnish  sufficient  pure  water  for 
particularly  delicate  operations.  All  water  used  for  assay 
purposes  should  be  evaporated  upon  a  clean  platinum  strip 
for  the  detection  of  any  permanent  salts,  and  should  be 
tested  for  chlorine  (by  silver  nitrate)  and  for  CO2  (by  lime 
water  or  acetate  of  lead),  if  no  stain  is  formed  after  evapo- 
ration, and  no  effects  from  the  reagents  just  mentioned,  it 
may  be  used  instead  of  distilled  water.  When  the  wind 
blows  from  the  direction  of  the  ocean  the  salt  may  be  de- 
tected in  water  falling  even  60  miles  from  the  coast,  and 
during  such  rains  the  water  should  not  be  collected  until  the 
storms  or  rains  come  from  other  directions. 

A  List  of  usual  Chemical  Apparatus. 

For  a  private  laboratory  the  following  apparatus  is  neces- 
sary : — 

Beaker  glasses,  one  nest. 

Several  flasks,  from  8  to  16  oz.  Three  with  flat  bottoms 
called  matrasses. 

Half  dozen  test  tubes,  medium  sizes,  with  a  test  tube  stand. 

Porcelain  dish,  two  sizes.     6  to  8  inches  across  top. 

Half  dozen  porcelain  crucibles  with  covers,  of  about  1  oz. 
volume. 

One  pipette.    Two  or  three  feet  of  glass  tubing  J  inch  bore. 

Glass  funnel,  medium  size.  The  sides  must  be  straight 
not  bulging. 


72  MINERALS,    MINES,   AND   MINING. 

One  dozen  glass  stopped  narrow- mouthed  bottles,  half  of 
them  6  oz.  size. 

Half  dozen  wide-mouthed  glass  bottles  from  6  to  8  oz.  size. 
.  One  nest  Hessian  crucibles  for  dry  assay. 

The  following  chemicals  : — 

Nitric  acid,  hydrochloric  acid,  sulphuric  acid. 

Caustic  soda,  caustic  potass,  aqua  ammonia,  alcohol,  one 
ounce  litmus,  molybdic  acid,  silk  bolting  cloth  from  the  miller. 
Pure  filtering  paper. 

The  following  may  be  bought  or  made  in  the  laboratory : 
oxalate  of  ammonium,  chloride  of  ammonium,  sulphate  of 
magnesium,  phosphate  of  sodium,  chloride  of  barium,  nitrate 
of  silver,  sulphide  of  iron,  permanganate  of  potassium,  hy- 
drosulphide  of  ammonium,  and  for  any  other  reagents  beyond 
these  the  preceding  list  may  be  consulted.  But  the  above 
are  necessary  for  the  beginner. 

To  the  above  apparatus  we  may  add  the  alcoholic  lamp 
which  may  be  of  glass  with  ground-glass  top,  or  of  metal 
made  by  the  tinner  with  a  perforated  cork  for  a  cap  for  the 
wick.  But  for  the  laboratory,  where  gas  is  not  ready  at 
hand,  one  of  the  most  useful  lamps  is  the  alcoholic  blast 
lamp  which  is  used  for  heating,  to  redness,  refractory  ores 
and  other  assays  in  the  crucible,  and  for  drying  and  cal- 
cining assays,  bending  tubes,  etc. 

Where  the  beginner  does  not  choose  to  make  his  own 
stand  for  holding  his  evaporating  dishes,  etc.,  over  the  flame, 
he  may  purchase  either  the  wooden  or  iron  stands  as  seen  in 


LIST   OF   USUAL  CHEMICAL   APPARATUS.  73 

the  catalogues  of  the  chemical  goods  and  apparatuses  of  any 
dealer.  So,  also,  as  to  test-tube  holders,  etc. 

We  have  given  the  above  list  and  directions  as  presenting 
about  the  smallest  stock  with  which  the  student  in  analysis 
can  begin,  and  to  this  we  should  add  the  platinum  crucible, 
which,  after  a  while,  he  will  have  to  purchase,  with  its  cap- 
sule, and  it  would  be  well  if  he  added  among  the  necessaries 
the  blowpipe. 

To  those  articles  which  we  have  mentioned  above,  the 
beginner  may  add  as  he  progresses,  but  he  should  keep  in 
mind  the  fact  that  some  of  the  best  analysts  in  Europe 
and  America  have  met  with  their  greatest  successes  while 
using  very  simple  appliances  in  kind  and  very  few  in  num- 
ber beyond  those  which  were  of  their  own  manufacture  or 
invention. 

IN  FOLDING  FILTER  PAPERS  the  simplest  way  is  to  fold 
them  half  over  and  then  quarter  and  so  on  until  the  pleats 
are  about  quarter  to  half  inch,  and  then  opening  them  part 
way,  push  the  whole  down  into  the  funnel  through  which 
the  filtration  is  to  be  performed.  Always  before  using  a 
filter  paper  hold  it  up  to  the  light  and  examine  if  there  be 
any  thin  spots  where  there  may  be  an  opening  and  reject  it 
if  the  appearance  is  very  nearly  that  of  a  hole,  as  frequently, 
under  these  conditions,  the  paper  is  likely  to  let  the  whole 
assay  down  at  once. 

WHERE  THE  LOWER  PART  OF  THE  INVERTED  CONE  of  the  fun- 
nel is  as  wide  as  a  half  inch,  or  a  little  less,  it  is  advisable 
to  make  a  little  inverted  cone  of  platinum  foil  just  large 
enough  to  cover  the  hole  and  let  the  sharp  end  of  the  filter 


74  MINERALS,   MINES,    AND   MINING. 

paper  fit  into  the  cone.  This  will  act  as  a  brace  to  the 
paper  and  the  filtrate  will  pass  through  just  as  well  as 
before.  Nothing  must  be  filtrated  over  this  which  would 
dissolve  any  of  the  platinum  (as  aqua  regia  or  nitro-muriatic 
acid)  but  generally  where  filtrates  are  rapidly  made  and 
weakened  very  soon,  this  evil  result  is  seldom  to  be  appre- 
hended. 

In  order  to  make  the  platinum  cone  fit  well,  a  neatly 
fitted  small,  or  miniature,  funnel  may  be  made  of  writing 
paper  dampened  and  closely  pressed  up  against  the  glass 
sides  of  the  funnel  in  that  part  for  which  the  platinum  is  to 
be  fitted.  Then  prepare  a  thick  cream  of  plaster  of  Paris 
with  some  two  or  three  drops  of  gum-arabic  solution  in  water 
with  which  the  cream  is  made,  the  amount  of  plaster  being 
only  enough  to  fill  the  bottom  part  of  the  funnel  where  the 
paper  is.  Pour,  when  well  mixed,  this  mixture  into  the 
funnel  very  slowly  till  it  begins  to  set,  or  stiffen,  which  it 
will  not  do  for  some  minute  or  two,  because  of  the  gum- 
arabic  solution.  Pour  all  in  and  let  it  harden,  thrusting  into 
the  mixture  a  small  rod  of  wood,  three  or  four  inches  long 
by  which  to  draw  it  out  when  hard.  Let  it  stand  for  an 
hour,  draw  it  out,  remove  the  damp  paper,  and  when  quite 
hard  it  is  ready  to  mould  the  platinum  upon.  In  order  to 
do  this,  make  a  paper  funnel  of  the  exact  size  wanted,  then 
laying  this  upon  the  platinum  carefully  mark  out  the  size 
and  cut  the  platinum  and  fit  it  upon  the  plaster  cone  which 
when  dry  will  be  found  nearly  as  hard  as  a  piece  of  marble. 
Burnish  it  down,  fitting  it  neatly,  then  place  it  in  the  funnel 


LIST   OF   USUAL   CHEMICAL   APPARATUS. 


75 


and  it  will  exactly  fit  and  will  allow  a  great  pressure  upon 
the  filter  paper  without  breaking  the  paper. 

If  a  jar  have  a  large  cork  fitted  nicely  into  the  top,  and  a 
hole  be  cut  into  which  this  funnel  may  fit  air-tight,  and 
another  hole  cut  for  another  tube  bent  at  an  angle  and  fitted 
in  air-tight,  we  shall  now  have  an  apparatus  for  rapid  filter- 
ing. If  when  filtering  is  going  on  through  the  funnel,  the 
mouth  be  applied  to  the  second  tube  and  the  air  drawn  out 
the  water  will  run  through  the  filter  with  a  rapidity  propor- 
tioned to  the  vacuum  formed  in  the  jar. 

Two  thin  sheet  copper  cans,  of  the  size  of  half  gallon  jars, 
may  be  made  to  make  the  vacuum  desired  for  rapid  filtering 
and  after  this  contrivance : — 

Fig.  3. 


A  and  B  are  the  two  copper,  or  tinned  copper,  cans  con- 
nected  by  a  rubber  tube.     D  is  a  glass  jar  used  for  this 


76  MINERALS,   MINES,   AND   MINING. 

method  of  filtering.  Use  pinch  stops,  or  clips,  at  S  S  S  to 
arrest  the  flow  when  such  arrest  is  necessary ;  open  the  tube 
at  the  lowest  S  and  that  near  A,  and  the  water  will  flow 
into  the  lowest  reservoir  B  and  create  a  partial  vacuum  in  A. 
Open  the  tube  at  S  nearest  to  D  and  a  similar  vacuum  is 
formed  in  D  and  the  filtration  begins  and  proceeds  rapidly 
in  proportion  to  the  perpendicular  distance  of  the  two  reser- 
voirs. When  the  lower  one  is  filled,  exchange  place  and 
tubes  and  the  process  is  renewed.  In  order  to  separate  the 
rubber  connection  from  the  filter  jar,  the  tin  or  glass  tube 
in  the  jar  should  be  very  nearly  of  the  size  of  the  opening 
of  the  rubber  tube,  so  that  it  may  slip  off  easily ;  it  may  be 
wrapped  with  a  cotton  thread  if  it  is  not  sufficiently  tight. 
Of  course  stopcocks  of  a  small  size  costing  more  would  be 
more  convenient  and  indeed  they  must  be  used  where  great 
pressure  is  adopted,  since,  in  that  case,  stronger  rubber  tubes 
must  be  used,  so  strong  and  thick  that  pinch-stops  would 
not  close  the  tube.  The  operator  must  consult  his  own 
judgment  as  to  the  pressure  desired.  Ten  feet  apart  for  the 
cans  is  sufficient  distance  for  ordinary  use,  and  less  will  be 
a  great  saving  in  time  expended  in  washing,  or  filtering,  and, 
with  a  little  care  and  ingenuity,  small  wide-mouthed  flasks 
may  be  used,  but  a  glass  jar  is  strong  and  may  readily  be 
emptied  of  its  contents  despite  the  shoulder,  provided  the 
angle  of  the  shoulder  is  not  too  nearly  that  of  a  right  angle. 
The  use  of  the  wash  bottle,  or  pipette,  will  aid  in  the  clear- 
ing out  any  remains  of  the  filtrate  where  that  is  to  be 
transferred  from  the  jar  to  the  beaker  glass.  A  block  of 
wood  may  be  fitted  into  a  jar  with  rubber  band  around  the 


LIST   OF   USUAL   CHEMICAL   APPARATUS.  77 

edge,  so  as  to  make  an  air-tight  joint,  and  it  may  be  easily 
removed  and  as  easily  replaced. 

PLATINUM  CRUCIBLES  should  not  be  too  thin,  and  should  be 
heated  over  an  alcohol  lamp,  but  as  little  as  possible  with  the 
ordinary  city  gas,  as  that  induces  roughness  and  incipient 
corrosion.  Although  caustic  alkalies  (potash  and  soda)  must 
sometimes  be  heated  to  red  heat  in  the  platinum  crucible, 
and  thereby  some  wearing  away  by  corrosion  of  the  crucible 
takes  place,  this  cannot  be  avoided,  and  the  only  alternative 
is  to  weigh  the  perfectly  clean  crucible  frequently  to  notice 
the  decreased  weight  so  as  to  keep  an  accurate  account  for 
such  assays  as  must  be  weighed  with  the  crucible,  and  the 
weight  of  the  crucible  subtracted.  The  action  of  alkalies 
treated  in  the  way  above  described  might  cut  holes  in  the 
porcelain  crucible,  hence  they  should  not  be  used,  except 
where  the  destruction  of  the  crucible  and  the  additional 
impurity  of  the  substance  of  the  crucible  are  of  no  import- 
ance in  the  result  desired. 

Brasque  is  the  term  used  to  express  the  condition  of  a 
crucible,  usually  Hessian,  which  has  been  lined  inside  with 
charcoal.  In  order  to  perform  this  work  it  is  best  to  mix 
some  powdered  charcoal  with  molasses  to  the  consistency  of 
thick  paste  and  with  a  paddle-formed  stick  line  the  sides 
thoroughly,  leaving  no  part  unlined.  In  some  cases  where 
the  crucible  is  small  it  is  well  to  fill  it  full  with  the  mixture, 
pressing  it  down  hard,  and  then  cutting  the  hole  out  with  a 
pointed  knife.  After  gradually  heating  till  all  the  vapor 
and  gas  from  the  molasses  has  passed  off,  and,  smoothing 
inside,  the  crucible  is  ready  for  work.  When  covered 


78  MINERALS,   MINES,   AND   MINING. 

tightly  over  by  a  piece  of  tile  or  brick  (luted),  ores  may  be 
reduced  under  great  heat,  and  neither  the  slag  nor  metal  can 
attack  or  injure  the  crucible,  and  slag  can  be  separated  easily 
from  the  crucible  which,  without  the  brasque,  would  cut 
holes  into  the  sides. 

Fuming  nitric  add  is  sometimes  of  great  use  in  the  reduc- 
tion of  stubborn  sulphides  and  in  some  other  operations.  It 
is  easily  made  from  dry  and  broken  up  saltpetre  (potassium 
nitrate).  Use  a  pint  or  quart  tubulated  glass  retort  placed 
in  a  retort  stand.  Put  in  only  about  half  a  pound  of  salt- 
petre, and  pour  over  the  saltpetre  enough  undiluted  •  sul- 
phuric acid  to  cover  the  contents.  Introduce  the  beak  of 
the  retort  into  a  glass  stopped  bottle,  which  should  better  be 
surrounded  by  ice  or  cold  water.  After  everything  is  ar- 
ranged apply  heat  by  either  an  alcoholic  flame  or  coal  oil 
light  set  so  as  not  to  smoke  the  glass.  The  acid  soon  comes 
over  and  is  condensed  in  the  bottle.  After  all  condensation 
ceases,  withdraw  the  bottle,  introduce  the  stopper,  and  set  the 
yellowish-looking  fuming  acid  away  out  of  light  and  in  a 
cool  place.  The  residue  in  the  retort  may  be  purified  by 
recrystallization  and  used  as  disulphate  of  potash  in  assays 
as  directed  in  the  text.  But  as  a  flux  for  some  very  stub- 
born ores,  as  those  of  chromic  iron  and  aluminous  minerals, 
where  it  may  be  used  for  making  them  soluble  in  acids,  the 
following  additional  preparation  is  necessary  :  Test  some  of 
the  recrystallization  for  lead,  or  arsenic,  which  may  have 
existed  in  the  sulphuric  acid  used.  Recrystallization  will 
render  it  sufficiently  pure.  Then  mix  87  parts  (weight) 
crystals  (dry)  with  49  parts  pure  sulphuric  acid,  and  heat  to 


LIST   OF   USUAL   CHEMICAL   APPARATUS.  79 

low  redness  until  the  mass  is  in  limpid  fusion.  A  platinum 
crucible  should  be  used,  and  the  work  repeated,  if  the  cruci- 
ble is  small,  to  obtain  sufficient  quantity.  Pour  out  the 
melted  mass  on  a  porcelain  plate  or  fragment.  After  cool- 
ing break  the  mass  into  pieces  and  keep  in  a  bottle  for  use. 

While  some  chemists  advise  the  use  of  potassium  disul- 
phate, others  (J.  Lawrence  Smith,  for  instance)  think  that 
sodium  disulphate  is  much  more  soluble  in  water  after  the 
same  ore  treatment. 

SODIUM  DISULPHATE  is  used  with  powdered  assays  in  the 
same  way  as  the  disulphate  of  potassium,  but  is  considered 
much  more  soluble  in  water,  after  the  ore  or  assay  treatment. 

The  preparation  is  similar  to  that  of  potassium  disulphate 
only  that  Glauber's  salt  (sulphate  of  soda)  of  the  shops  is 
used  and  purified  by  crystallization  exactly  as  in  the  pre- 
viously mentioned  disiilphate  of  potassium.  The  salt  should 
be  heated  at  a  gentle  heat  to  drive  off  its  water  of  crystalliza- 
tion. Then  7  parts  of  salt  to  5  parts  pure  sulphuric  acid 
should  be  heated  to  low  redness  in  a  platinum  crucible  or 
dish,  and  all  treated  as  in  the  case  of  the  potassium  disul- 
phate. 


ECONOMIC  TREATMENT  AND  HISTORY  OF  THE 
USEFUL  MINERALS. 


IN  the  following  pages  we  shall  treat  of  all  the  important 
minerals  in  order.  We  have  proceeded  upon  the  principle 
of  stating  that  which  most  recent  discovery  or  experiment 
has  shown  to  be  most  probable  in  the  economic  history  or 
most  efficient  in  the  treatment  of  that  particular  mineral 
under  consideration,  and  generally  omitting  unimportant 
statements  and  suggestions,  however  recent  or  novel,  except- 
ing where  such  statements  and  suggestions  might  render 
clearer  what  has  already  been  stated. 

Especially  in  the  analysis  or  the  determination  of  a  mineral 
we  have  frequently  had  reason  to  feel  that  one  good  method 
skilfully  pursued  was  followed  by  better  results  than  another 
which,  although  better  in  some  degree,  was  attended  with 
certain  complications  or  requirements  which  rendered  it 
uncertain  as  to  results  or  unnecessary. 

The  student  who  has  made  himself  acquainted  with  the 
work  and  suggestions  of  the  previous  pages,  will  find  little 
difficulty  in  understanding  the  references  in  the  following 
pages. 

The  hardness  of  a  mineral  is  always  compared  with  that 
of  the  diamond  rated  at  ten,  and  the  scale  of  descent,  in 


82  MINERALS,   MINES,   AND   MINING. 

degree,  may  be  formed  by  comparison  with  the  following 
substances,  which  may  be  obtained  from  any  mineral  collec- 
tion, or  salesman,  remembering  that  the  samples  must  be  as 
pure  as  can  be  obtained,  preferably  in  crystal  form,  and  also 
that  there  may  be  a  slight  difference  in  degree  in  hardness 
even  in  the  same  species,  so  that  determinations  must  be 
left,  in  some  small  degree,  to  the  judgment  of  the  miner- 
alogist. 

10.  Diamond. 

9.  Corundum  (pure  emery). 

8.  Spinel,  topaz. 

7.  Quartz  (rock  crystal),  Beryl  7.5,  Zircon  crystal  7.5. 

6.  Pyrite,  marcasite,  massive  red  hematite,  cassiterite,  gar- 
net 6.5,  feldspars  6  to  7. 

-5.  Leucopyrite,  mispickel  (arsenopyrite)  5.5,  fibrous  limo- 
nite  homogeneous  specimen,  apatite. 

4.  Zinc  blende  (sphalerite)  3.5  to  4,  fluor  spar  4,  zincite 
(red  oxide)  4.5. 

3.  Calcite  (crystalline  specimens)  common  2.5  to  3.5,  pyr- 
rhotite  3.5,  Barite  (Barytes  sulphate)  2.5  to  3.5. 

2.  Sulphur  (native)  (brimstone),  galena  2.5,  salt  (common) 
in  mass  or  crystals  2.5,  mica  (phlogopite)  2.5,  anthra- 
cite 2  to  2.5. 

1.  Graphite,  "  black  lead,"  native,  realgar  1.5,  sal  ammo- 
niac 1.5,  gypsum  1.5  to  2,  copal. 


GOLD.  83 


GOLD. 

OCCTJRRENT  CONDITION  AND    FORM  IN  NATURE.      NATIVE. — 

If  crystalline,  generally  in  that  pyramidal  form  known  as 
the  octahedral  or  eight-side  figure,  similar  to  that  which 
would  result  from  joining  together,  at  their  bases,  two  equi- 
lateral four-sided  pyramids.  Frequently  the  gold  occurs  in 
arborescent  forms,  and  in  one  specimen,  in  the  author's  pos- 
session, the  octahedral  form  occurs  only  at  the  termination 
of  the  arborescent  mass.  Also  in  irregular  masses  called 
nuggets,  in  flattened  scales,  in  particles  called  dust,  and  in 
various  intermediate  shapes,  appearing  as  though  the  gold 
had  been  melted  and  conformed  to  the  substances  in  which 
it  cooled.  It  is,  however,  very  improbable  that  all  such  gold 
was  melted,  certainly  some  masses  have  once  been  in  solu- 
tion in  some  liquid  anterior  to  the  time  when  they  assumed 
the  shapes  they  now  retain. 

HARDNESS  AND  SPECIFIC  GRAVITY. — Hardness  from  2.5  to 
3 ;  grav.  from  15  to  19.34,  the  latter  when  quite  pure  (Rose). 

COLOR  varies  from  dark  yellow,  when  quite  pure,  to  light 
yellow,  according  to  amount  of  silver  in  composition. 

DUCTILE  AND  EXTREMELY  MALLEABLE. 

COMPOSITION. — Native  gold  seldom,  if  ever,  occurs  pure. 
The  usual  alloy  is  silver,  but  sometimes  copper,  palladium, 
rhodium,  and  iron.  Judging  from  a  large  number  of  analy- 
ses, native  gold  always  contains  silver,  very  seldom  any  more 
than  a  trace  of  copper  and  iron.  Dana  mentions  (see  under 
gold)  one  analysis  showing  traces  of  tin,  lead,  and  cobalt,  and 


84  MINERALS,    MINES,    AND    MINING. 

one  having  a  trace  of  bismuth,  both  foreign  specimens.  In 
the  cases  of  alloys  with  palladium  and  rhodium,  of  the  former 
10  per  cent.,  of  the  latter  34  to  43  per  cent.  They  were 
rare  and  foreign  specimens,  and  not  worthy  of  further 
mention. 

UNITED  STATES  LOCALITIES. — Gold  is  widely  distributed, 
and  occurs  where  it  is  so  minutely  diffused  that  it  would  be 
a  loss  of  time  and  money  to  attempt  to  gather  it.  It  is  not 
surprising,  therefore,  that  gold  may  be  frequently  found 
where  no  useful  results  follow  the  rinding.  From  various 
authorities,  including  Dana,  Whitney,  Silliman,  and  others, 
we  gather  the  following  summary  showing  the  distribution, 
the  associations,  and  geologic  horizons  of  gold  as  generally 
met  with  in  the  United  States  and  Territories.  There  are 
numberless  mines  along  the  mountains  of  Western  America, 
and  others  along  the  eastern  range  of  the  Appalachians  from 
Alabama  and  Georgia  to  Labrador,  beside  some  indications 
of  gold  in  portions  of  the  intermediate  Azoic  region  about 
Lake  Superior.  They  occur  at  many  points  along  the  higher 
regions  of  the  Rocky  Mountains  ...  in  New  Mexico, 
near  Santa  Fe,  Carillos,  etc.,  in  Arizona,  in  the  San  Fran- 
sisco,  Wauba,  Yuma,  and  other  districts ;  in  Colorado  abun- 
dant, but  the  gold  is  largely  in  auriferous  pyrites;  in  Utah 
and  Idaho.  Also  along  ranges  between  the  summit  and  the 
Sierra  Nevada,  in  the  Humboldt  region,  and  elsewhere. 
Also  in  the  Sierra  Nevada,  mostly  on  its  western  slope  (the 
mines  of  the  eastern  being  principally  silver  mines).  The 
auriferous  belt  may  be  said  to  begin  in  the  California  Penin- 
sula. Near  the  Tejou  Pass  it  enters  California,  and  beyond, 


GOLD.  ,  85 

for  180  miles,  it  is  sparingly  auriferous,  the  slate  rocks  being 
of  small  breadth;  but  beyond  this,  northward,  the  slates 
increase  in  extent,  and  the  mines  in  number  and  productive- 
ness, and  they  continue  thus  for  200  miles  or  more. 

Gold  occurs  also  in  the  coast  range  in  many  localities, 
but  mostly  in  too  small  quantities  to  be  profitably  worked. 
The  regions  to  the  north  in  Oregon  and  Washington  Terri- 
tory are  at  many  points  auriferous,  and  productively  so, 
though  to  a  less  extent  than  in  California.  Gold  occurs  in 
Virginia,  North  and  South  Carolina,  and  Georgia,  or  along 
a  line  from  the  Rappahannock  to  the  Coosa  in  Alabama. 
But  the  region  may  be  said  to  extend  north  to  Canada ;  for 
gold  has  been  found  at  Albion  and  Madrid  in  Maine; 
Canaan  and  Lisbon  in  New  Hampshire ;  Bridge  water,  Ver- 
mont ;  Dedham,  Mass.  Traces  also  occur  in  Franconia 
Township,  Montgomery  Co.,  Pennsylvania.  In  Virginia,  the 
principal  deposits  are  in  Spotsylvania  Co.,  on  the  Rappahan- 
nock, at  the  United  States  mines  and  at  other  places  to  the 
southwest ;  in  Stafford  County  ten  miles  from  Falmouth ;  in 
Culpeper  County,  on  Rapidan  River ;  in  Orange,  Goochland, 
Louisa,  and  Buckingham  counties.  In  North  Carolina, 
chiefly  in  Montgomery,  Cabarrus,  Mecklenburg,  and  Lin- 
coln ;  in  the  alluvial  soil  in  the  counties  of  Burke,  McDowell, 
and  Rutherford.  In  Georgia,  in  Habersham  County,  and  in 
Rabun,  Hall,  Lumpkin,  at  Dahlonega,  and  in  Cherokee 
County.  In' South  Carolina,  the  principal  gold  regions  are 
the  Fair  forest  in  Union  District  and  the  Lynch 's  Creek  and 
Catawba  regions,  chiefly  in  Lancaster  and  Chesterfield 
Districts,  also  in  Pickens  District,  adjoining  Georgia.  (Dana.) 


86  MINERALS,   MINES,    AND    MINING. 

Prof.  Frank  H.  Bradley,  after  speaking  of  the  copper  mines 
at  Ducktown,  Polk  Co.,  Tennessee,  writes  that :  "  On  both 
sides  of  the  copper  leads,  but  most  abundantly  to  the  south, 
there  are  gold-bearing  schists,  in  which  small  operations  have 
been  carried  on  for  many  years.  The  only  point  in  Tennes- 
see which  has  attracted  special  attention  is  on  the  head 
waters  of  Coca  Creek.  The  '  placer'  deposits  are  but 
moderately  rich  and  of  rather  limited  area.  Gold-bearing 
quartz  veins  have  been  found  at  two  or  three  points,  but 
little  work  has  been  done  in  them.  Farther  south,  in 
Georgia,  the  decomposition  of  the  rocks  has  gone  on  to 
greater  depths,  more  material  has  been  concentrated,  and 
valuable  placer  properties  are  known  at  several  points ;  at 
two  or  three  points,  hydraulic  mining  is  carried  on  success- 
fully, as  in  the  region  about  Dahlonega.  I  think  that  there 
is  every  reason  to  believe  that  there  are  as  rich  mines  in 
Georgia  and  North  Carolina  as  any  in  California.  The 
Tennessee  deposits  have  been  but  little  known  thus  far;  but 
there  are  geological  reasons  for  expecting  that  good  mines 
will  yet  be  developed  there." 

The  Gold  Hill  mines  in  Rowan  Co.,  North  Carolina,  have 
produced  not  less  than  $2,000,000.  The  King's  Mountain 
mine  in  Gaston  Co.,  N.  C.,  is  said  to  have  produced  over 
$1,000,000,  and  that  of  the  Portis  mine  in  Eastern  North 
Carolina,  in  about  fifty  years,  over  $1,000,000. 

The  mines  of  South  America  and  Mexico  were  estimated 
by  Humboldt,  over  sixty  years  ago,  to  yield  annually 
§11,500,000,  which  much  exceeds  the  present  product.  The 
yield  of  California  in  1849,  the  first  year  after  the  discovery 


GOLD.  87 

of  the  gold,  was  $5,000,000.  The  yield  in  1853  was 
nearly  $60,000,000.  Since  then  it  has  diminished,  and  the 
amount  in  1866  was  $27,000,000.  Montana,  Colorado, 
Idaho,  and  Nevada  raised  the  total  from  the  United  States 
for  the  year  1866  to  $86,000,000.  The  same  fact  of  decrease 
may  be  shown  in  connection  with  the  gold  yield  of  Australia, 
from  $60,000,000  for  a  number  of  years  it  fell  to  $30,000,000 
in  1863,  1864,  1865,  the  sum  being  an  average  for  each  of 
these  years.  This  fact  of  decrease  of  the  gold  yield  in  min- 
ing districts  after  a  series  of  years,  inversely  considered,  sug- 
gests the  probability  that  large  amounts  of  gold  were  derived 
from  the  mines  of  ancient  times,  arid,  in  that  virgin  period 
of  gold  hunting,  the  metal  far  exceeded  in  quantity  any 
amount  which  in  these  latter  days  has  been  revealed. 

From  The  Mineral  Resources  of  the  United  States  (Wil- 
liams), 1885,  the  total  annual  production  of  gold  in  the 
United  States  from  the  year  1867  ($53,000,000)  decreased  to 
1875  ($32,000,000),  when  it  increased  to  1878  ($51,000,000), 
and  then  decreased  till  1883  ($30,000,000),  since  which  time 
it  has  been  on  the  increase.  The  greatest  annual  production 
was  in  1853,  $65,000,000.  In  1884,  December  31,  it  was 
reported  as  $31,000,000  ;  for  1886  it  is  given  by  the  Director 
of  the  Mint  at  $35,057,889. 

One  of  the  practical  suggestions  derived  from  the  fact  that 
estimates  of  the  above  nature  cannot  always  be  relied  upon, 
is  that  there  are  many  private  enterprises  the  reports  of  whose 
profits  are  not  made  public.  There  are  small  firms  or  com- 
panies, and  even  individuals,  content  to  make  comparatively 
small  sums,  who,  by  less  outlay  and  more  toil,  have  actually 


88  MINERALS,    MINES,   AND   MINING. 

done  better  than  large  companies.  These  have  never  re- 
ported. 

Alaska  is  growing  rapidly  into  a  gold  producing  country, 
although  in  1884  the  product,  $200,000,  was  a  third  less 
than  in  1883.  But  in  1881  it  was  only  $15,000,  in  1882 
$150,000,  in  1883  $300,000,  in  1886  $446,590.87. 

The  annual  output  of  gold  and  silver  in  the  United  States 
is  about  the  same  in  value  as  that  of  pig-iron  at  present 
prices,  but  far  below  the  value  of  the  coal  production.  (Wil- 
liams, 1885.) 

GEOLOGY  OF  GOLD  AND  ITS  ASSOCIATIONS. — There  is  no 
positive  evidence  that  gold  exists  in  nature  in  any  other 
than  the  metallic  state,  although  it  is  believed  by  some  to 
exist  as  a  sulphuret  in  some  varieties  of  pyrites.  (Bloxam.) 
And,  in  behalf  of  this  view,  it  may  be  offered  that  the  free 
gold  in  many  places  has  evidently  resulted  from  the  oxida- 
tion of  the  iron  pyrites  and  the  consequent  unclothing  of 
the  native  gold  embedded  in  the  pyrites.  If  some  auriferous 
pyrites  be  treated  carefully  with  nitric  acid,  particles  of  gold 
are  left  in  the  native  state,  although  there  was  apparently  no 
possible  method,  by  comminution  or  any  other  physical  treat- 
ment, of  discovering  the  gold,  even  by  the  microscope.  This 
has  been  tried  in  specimens  taken  from  the  Columbia  mines 
near  Helena,  Montana,  in  which  the  gold  appeal's  to  be 
almost  chemically  combined  with  the  pyrites  as  a  sulphide 
of  gold. 

Nevertheless,  gold  will  combine  with  sulphur  in  the 
laboratory,  to  form  two  GOLD  SULPHIDES:  (1)  Au2S,  At (rous 
sulphide,  formed  as  a  dark  brown,  almost  black  precipitate, 


GOLD.  89 

when  hydrogen  sulphide  is  passed  into  a  boiling  solution  of 
auric  chloride ;  (2)  Auric  sulphide,  Au2S3,  is  precipitated  in 
yellow  flocks  when  hydrogen  sulphide  is  passed  into  a  cold 
dilute  solution  of  auric  chloride. 

The  extent  to  which  gold  is  distributed  in  small  quantities 
is  remarkable,  for  there  are  few  countries  where  it  may  not 
be  found,  but,  in  many  cases,  in  such  finely  disseminated 
condition  as  to  offer  no  inducement  to  those  who  are  wise 
and  do  not  desire  to  lose  money  to  collect  it.  So  that  the 
discovery  of  gold  is  by  no  means  a  proof  that,  commercially 
speaking,  there  is  any  value  added  to  the  land  where  the 
gold  has  been  found,  or  that,  in  any  true  sense,  a  working 
on  that  land  may  be  called  a  gold  mine. 

Gold  has  been  found  in  Cornwall,  England,  in  the  same 
alluvial  deposits  wherein  tin  ore  occurs,  and  in  Konigsberg 
the  metallic  gold  is  disseminated  through  sulphuret  of  silver ; 
in  Edelfors  in  Smoland,  Sweden,  it  is  associated  with  pyrites. 
The  sands  of  the  Rhine  contain  minute  quantities  (eight 
million  parts  of  sand  to  one  of  gold),  and  yet  it  is  worked 
when  other  work  is  scarce.  (Bloxam.)  The  sands  of  the 
Danube,  Rhone,  Tagus,  and  many  other  European  rivers 
afford  gold  and  have  been,  at  different  periods,  worked  for 
this  metal. 

Veins  of  pyrites  containing  gold  are  found  in  a  granite 
rock  at  the  foot  of  Monte  Rosa.  (Bloxam.)  Siberia  yields 
gold  distributed  through  horn  stone. 

In  Australia  it  is  found  deposited  upon  pipe  clay  under 
the  alluvium. 

But  the  gold  of  the  world  has  been  mostly  gathered  from 


90  MINERALS,   MINES,    AND  MINING. 

the  gravels  and  sands  of  rivers,  and  the  sand  of  any  river  is 
worth  washing  for  the  gold  it  contains,  if  it  will  yield  24 
grains  in  a  hundred  weight;  and  provided,  always,  that 
labor  is  cheap.  The  sand  of  the  African  rivers,  however, 
often  yields  sixty-three  grains  of  gold  dust  in  not  more  than 
five  pounds  weight. 

Gold  occurs  in  rocks  of  various  ages,  from  the  Azoic  to 
the  Cretaceous  or  Tertiary,  but  the  in  situ  or  original  rock 
is  the  metamorphic  in  which  veins  of  quartz  are  found  tra- 
versing the  metamorphic  and  charged  with  gold  in  strings, 
plates,  scales,  and  masses  of  crystals.  (Dana.)  Many  theo- 
ries are  offered  for  its  appearance  which  are  not  important, 
but  gold  is  generally  found  in  the  crystalline  rocks,  or  is 
derived  from  such  rocks,  after  these  rocks  have  through  ages 
become  disintegrated  and  carried  away  by  means  of  the  trans- 
porting agency  of  water. 

It  is  plain,  therefore,  that  the  mineralogist  should  be 
largely  guided  by  the  geologic  intimations  in  his  explora- 
tions for  this  metal. 

Very  frequently  the  strata  which  bear  gold  are  not  dis- 
tinctly defined  or  separated  from  those  strata,  or  parts  of 
strata,  which  are  entirely  barren.  So  that  nothing  in  the 
nature  of  the  rock  can,  in  all  .cases,  determine  it  as  gold- 
bearing.  This  is  frequently  illustrated  in  North  Carolina, 
where,  according  to  Dr.  Genth,  "  it  (the  gold)  has  been  acted 
upon  by  chemical  agencies,  dissolved  and  precipitated  again, 
and  has  assumed  a  crystalline  structure ;  it  has  accumulated 
in  strings  which  sometimes  form  lenticular  and  more  highly 
auriferous  masses  in  the  beds,  and  is  associated  with  crystal- 


GOLD.  91 

line  quartz,  pyrite,  chalcopyrite,  galenite,  blende,  mispickel, 


etc." 


In  King's  Mountain  mine,  of  Gaston  Co.,  N.  C.,  the  gold 
is,  to  a  great  extent,  contained  in  a  quartzoze  limestone,  and 
is  associated  with  very  small  quantities  of  pyrite,  galenite, 
chalcopyrite,  but  also  with  the  very  rare  tellurides  of  lead, 
altaite,  and  with  nagyagite,  a  telluride  of  gold  and  lead.  In 
some  places  this  ore  bed  is  over  thirty  feet  in  thickness,  and 
has  been  worked  to  a  depth  of  200  feet,  but,  longitudinally, 
only  to  a  very  small  extent,  not  over  250  feet.  (Journal  of 
the  Franklin  Institute,  January,  1872.) 

In  North  Carolina,  the  gold,  though  originally  found  in 
nuggets,  is  now  generally  found  in  grains  and  in  fine  dust, 
its  average  fineness  being  825  thousandths,  and  is  associated 
with  platinum,  diamond,  zircon,  xenotime,  menazite,  and 
many  other  minerals.  (Genth.)  At  the  Portis  mine,  in  the 
eastern  part  of  the  State,  the  gold  is  generally  about  985 
thousandths  fine,  and  in  the  gravel  beds. 

Those  deposits  which  have  been  formed  from  a  decompo- 
sition of  gold-bearing  rocks,  which  has  been  carried  on 
through  ages,  are  the  most  valuable,  as  nature  has  concen- 
trated the  nuggets  or  particles  at  the  bottom  of  the  sand, 
gravel,  or  loose  material,  and,  in  some  instances,  has  given 
an  additional  power  of  gravitation  to  the  gangue  rocks  which 
held  gold,  so  that  they  have  parted  companionship  with  frag- 
ments which  were  barren.  The  most  extensive  gravel  de- 
posits exist  in  the  South  Mountains,  on  the  head  waters  of 
the  first  and  second  Broad  River,  Muddy  Creek,  and  Silver 
Creek,  in  the  counties  of  Rutherford,  McDowell,  Burke, 


92  MINERALS,   MINES,   AND   MINING. 

Caldwell,  also  in  Polk  and  Cleveland,  embracing  an  area  of 
over  200  square  miles  (Genth).  Even  the  soil  and  clay, 
which  cover  these  beds  in  some  places,  are  more  or  less  auri- 
ferous, although  poorer  than  the  gravel  beds. 

A  peculiarity  in  the  North  Carolina  gravel  beds  is  found 
in  that  the  attempt  to  work  the  gravel,  as  a  mass,  for  gold, 
by  crushing  it,  was  a  failure,  inasmuch  as  the  fine  or  small 
quartz  veins  were  the  gold-bearing  veins,  and  not  the  large 
quartz  veins ;  this  fact,  with  that  derived  from  that  which 
has  already  been  stated  as  to  natural  concentration,  explains 
the  cause  of  failure. 

In  Montgomery  County  there  are  gravel  deposits  in  the 
slate  formation,  some  of  which  have  proved  highly  import- 
ant, yielding  nuggets  and  crystalline  flat  pieces  with  very 
little  fine  grained  gold. 

The  average  fineness  of  California  native  gold,  as  deduced 
from  thousands  of  assays  at  the  Philadelphia  Mint,  is  88J 
parts  gold,  and  11|  parts  silver  in  100  parts. 

For  the  following  additional  remarks  we  are  indebted  to 
the  late  Wm.  E.  Du  Bois,  chief  assayer  of  the  U.  S.  Mint, 
Philadelphia,  Pa. 

Native  gold,  or  silver,  does  not  occur  absolutely  pure,  yet 
sometimes  so  near  it  that  it  would  be  called  such,  commer- 
cially. Gold  grains  have  resulted  998.  Silver  will  more 
nearly  approach  1000:  still  there  is  something  between  it 
and  the  chemist's  refinement.  In  fact  it  is  a  pretty  high 
attainment  of  our  art  to  make  these  metals  chemically  pure, 
and  fit  for  proofs. 

We  have  found  a  wide  diversity,  and  a  vast  variety  in  the 


GOLD.  93 

fineness  of  California  gold.  It  has  resulted  as  low  as  812, 
and  as  high  as  957,  the  general  average  is  probably  880  to 
885. 

The  alloying  metal  is  silver  and  the  two  together  will, 
after  melting,  generally  show  995  parts  of  precious  metal, 
the  remaining  5  parts  being  the  oxide  of  iron,  which  covers 
and  permeates  every  grain.  It  is  this  which  gives  such  high 
and  deceptive  coloring  to  the  native  gold.  It  is  quite  sur- 
prising to  see  the  same  gold,  before  and  after  melting ;  being 
so  much  paler  in  the  latter  case. 

There  is  however  before  melting  a  larger  association  than 
that  of  base  matter;  for  in  the  melting  there  is  a  removal 
of  2 1  to  4  per  cent,  of  the  original  weight ;  the  5  thousandths 
just  spoken  of  still  remaining  in  the  alloy  as  a  trace.  In 
the  parting  process  this  last  trace  disappears. 

In  the  earlier  days  of  California  gold  a  few  samples  were 
assayed  by  eminent  chemists  in  Paris,  and  they  actually 
asserted  a  union  of  gold  and  silver  in  atomic  proportions. 
A  larger  experience,  it  might  be  said  a  little  reflection, 
would  have  convinced  them  of  the  absurdity  of  such  an  idea. 
And  yet  that  statement  is  seen  copied  from  one  book  to 
another,  even  down  to  a  very  recent  work  on  assaying  by  a 
high  authority. 

Gold  and  silver  are  found  together  in  every  possible  grade 
of  proportion.  It  is  only  in  the  very  rare  case  of  a  natural 
crystalline  structure  that  the  proportion  can  be  supposed  to 
be  atomic,  so  that  this  affirmation  should  not  be  copied, 
although  made  even  by  so  high  an  authority  (if  we  mistake 
not)  as  Boussingault. 


94  MINERALS,   MINES,   AND   MINING. 

The  gold  of  North  Carolina  has  to  a  large  extent  the  same 
range  of  fineness  as  that  of  California ;  but  in  an  extreme 
case  (mentioned  by  Mr.  Frederick  Eckfeldt  to  Mr.  Du  Bois) 
it  came  out  991.  Its  average  is  lower  than  that  of  Cali- 
fornia. Georgia,  Tennessee,  and  Alabama,  on  the  other 
hand,  are  considerably  higher.  In  Nova  Scotia  there  are 
two  general  classes,  one  of  them  quite  high,  the  other  below 
our  standard. 

The  differences  in  the  gold  of  Australia  are  very  marked. 
They  classify  their  mines  as  Northern,  Western,  and  South- 
ern. In  the  first,  the  range  has  been  found  from  654  to  962, 
with  an  average  below  900;  the  Western  mines  run  from 
915  to  960;  the  Southern  928  to  983.  We  have  considered 
Australian  gold  to  find  an  average  at  960 ;  doubtless  from 
Southern  mines.  To  all  these  classes,  in  which  gold  pre- 
ponderates, the  new  chlorine  refining  and  parting  process, 
invented  and  perfected  by  F.  Bowyer  Miller,  Esq.,  of  the 
Melbourne  (formerly  of  the  Sydney)  Mint,  is  admirably 
adapted.  He  was  at  the  U.  S.  Mint,  Philadelphia,  in  1871, 
and  exhibited  his  process  of  working  it  [by  passing  chlorine 
through  the  melted  metal]. 

The  gold  of  Colorado  is  generally  pale ;  that  of  Montana 
is  higher  in  per  cent.,  but  of  so  varied  grades  that  the  average 
can  hardly  be  better  stated. 

The  natural  alloys  and  accompaniments  of  gold  present  a 
large  and  curious  study.  Can  any  plausible  reason  be  given 
why  silver  is  always  in  company  with  gold,  and  copper 
almost  never'?  And  yet,  when  we  come  to  make  a  mixture 
artificially,  gold  takes  to  copper  more  keenly  than  silver 


GOLD.  95 

does.  The  following  is  a  note  of  an  experiment  by  Mr.  J.  R,. 
Eckfeldt  made  some  years  ago. 

A  prise  of  900  parts  gold  +  100  copper;  and  another  of 
900  silver  -f  100  copper,  were  made  upon  the  the  assay-beam, 
wrapped  in  lead  foil,  and  placed  in  cupels  side  by  side. 
They  were  subjected  to  a  high  heat  in  the  oven.  When 
taken  out  the  gold  button  was  found  to  retain  23  parts 
copper.  The  silver  lost  all  its  copper. 

While  speaking  of  gold  affinities  and  alloys  two  other 
curious  facts  must  be  noticed.  One  is,  that  gold  in  its 
natural  condition  is  usually  found  in  the  motherly  embrace 
of  iron  in  some  mineralized  form,  say  oxide  or  sulphide. 
And,  yet,  an  attempt  to  unite  them  in  a  crucible  will  be  un- 
successful. They  will  not  mix,  except  in  an  imperfect, 
heterogeneous  way. 

But  the  other  more  curious  fact,  which,  like  many  others, 
warns  science  rather  to  seek  for  facts  than  to  attempt  to 
account  for  them,  is  found  in  this,  that  lead,  in  its  native 
mineral  form,  is  sure  to  contain  both  silver  and  gold,  yet, 
chiefly,  in  infinitesimal  proportions.  Spanish  pig  lead, 
which  of  all  the  commercial  leads  is  the  freest  from  silver, 
has  been  found  containing  one-third  of  an  ounce  to  the  ton ; 
and  when  that  silver  was  dissolved,  it  was  found  to  contain 
gold. 

A  very  remarkable  case  was  that  of  galena  found  in  New 
Britain,  Bucks  County,  Pa.,  where  Mr.  Eckfeldt  found  2J 
grains  of  gold,  say  ten  cents'  worth,  to  the  ton  of  lead. 

Now,  by  what   imaginable   process  of  nature   do    these 


96  MINERALS,   MINES,    AND   MINING. 

atoms  of  silver  and  gold  find  place  in  this  base  metal,  and  in 
such  proportions  1 

METHODS  OF  TREATING  GOLD  ALLOYS. 

In  a  foreign  periodical  we  find  the  following  statements 
which  contain  much  which  is  important  in  the  refining  of 
gold. 

In  the  Mint  of  the  United  States,  ferruginous  gold  is 
melted  with  a  mixture  of  sulphur,  and  carbonate  of  potash 
and  soda ;  tin,  antimony,  and  arsenic  are  removed  by  melt- 
ing with  borax,  soda,  and  saltpetre,  or  according  to  Waring- 
ton,  tin  and  antimony  may  be  extracted  by  melting  the  gold 
for  half  an  hour  with  one-tenth  of  its  weight  of  oxide  of 
copper  and  some  borax.  Lead  may  be  removed  by  melting 
with  saltpetre  and  sand,  or  a  little  chloride  of  mercury 
enveloped  in  paper  is  repeatedly  thrown  into  the  mass,  fused 
with  saltpetre  and  borax,  until  a  sample  taken  shows  suffi- 
cient ductility.  0.02  per  cent,  of  lead  renders  gold  brittle. 

Pettenkofer  states  that  almost  all  extracted  gold  contains 
a  small  amount  of  platinum,  from  which  it  may  be  freed  as 
oxide  of  platinum  and  potash  by  melting  with  saltpetre. 
This  amount  of  platinum  not  only  retains  silver  in  gold,  but 
causes  a  considerable  loss  of  gold  when  melting  it  with  salt- 
petre. Whilst  finely  divided  gold  when  melted  with  salt- 
petre oxidizes  with  more  difficulty  than  platinum,  it  oxidizes 
most  readily  in  the  presence  of  platinum,  forming  slags 
containing  as  much  as  19  or  20  per  cent,  of  gold  and  2|  or 
3|  per  cent,  of  platinum.  If  the  gold  also  contains  silver, 
the  silver  protects  the  platinum  from  oxidation,  and  the 


GOLD.  97 

platinum  then  enters  the  argentiferous  gold.  All  the  plati- 
num will  enter  the  slags  if  the  gold  contains  not  more  than 
0.5  per  cent,  of  silver,  and  not  more  than  0.3  per  cent,  of 
platinum.  Besides  the  potash  of  the  saltpetre,  the  slags 
contain  all  the  metals  which  were  attacked  at  the  previous 
treatment  with  sulphuric  acid,  and  transformed  into  insoluble 
salts  (sulphate  of  lead,  sulphide  of  copper,  basic  sulphate  of 
iron)  ;  some  components  of  the  crucible  (silica,  alumina, 
lime)  also  enter  the  slags,  and  metallic  oxides  formed  by 
the  reaction  of  the  saltpetre  upon  the  metals  (oxides  of  gold, 
platinum,  palladium,  osmium).  Some  fine  gold  and  some 
silver  grains  are  also  mechanically  included,  owing  to  the 
great  viscosity  of  the  slags. 

Experience  shows  the  best  admixture  for  smelting  to  be 
16  parts  of  gold  with  1  part  of  saltpetre,  when  the  resulting 
slag  will  weigh  about  as  much  as  the  saltpetre  employed. 
The  average  loss  of  gold  by  the  slag  is  1  per  cent,  when 
using  saltpetre  in  that  proportion ;  an  addition  of  borax 
renders  the  slag  more  liquid. 

The  whole  of  the  small  amount  of  platinum  in  the  gold 
usually  enters  the  slag. 

The  amount  of  gold  grains  in  the  slag  depends  chiefly  on 
the  quantity  of  gold  smelted.  If  larger  quantities  of  gold 
are  melted  in  one  charge,  the  relative  and  absolute  amount 
of  gold  in  the  slag  will  always '  be  much  larger  than  when 
melting  the  same  quantity  in  different  operations ;  it  is  best 
to  melt  exactly  10  Ibs.  in  one  operation,  as  when  employing 
crucibles  of  equal  size  the  trough  slag  stands  higher  in  the 

crucible  than  when  melting  smaller  quantities.     The  higher 

7 


98  MINERALS,   MINES,   AND    MINING. 

the  slag  stands  in  the  crucible  the  more  the  sinking  of  the 
gold  grains  is  impeded.  Sometimes  a  skin,  consisting  of  fine 
grains  of  metallic  gold,  is  formed  on  the  lower  side  of  the 
slag,  caused  by  the  sinking  of  gold  grains  after  the  tempera- 
ture has  decreased  below  the  melting  point  of  gold,  whilst 
the  slag  is  kept  liquid  ;  the  gold  grains  cannot  then  unite 
either  with  each  other  or  with  the  gold  below.  When  melt- 
ing small  quantities  of  gold  the  slag  formed  is  also  propor- 
tionally thinner,  retaining  for  that  reason  fewer  grains  of 
gold.  The  crucible  is  liable  to  corrosion  by  the  potash 
present  when  trying  to  render  larger  quantities  of  slag 
more  fluid  by  a  continued  firing. 

The  reverse  takes  place  with  any  silver  in  the  slag.  The 
particles  of  silver  still  contained  in  the  gold  remain  sus- 
pended in  the  slag  together  with  some  gold,  owing  to  the 
light  specific  gravity  and  the  fine  distribution  of  silver,  and 
they  sink  more  slowly  the  thinner  the  slag  is.  Therefore 
one  and  the  same  quality  of  gold  alloy  will  yield  gold  of 
greater  fineness  (by  0.001  or  0.002)  when  melted  in  larger 
quantities  than  when  melted  in  smaller  lots. 

To  extract  gold  and  platinum  from  the  slag,  Pettenkofer 
recommends  that  they  should  be  mixed  with  water  to  a  thin 
paste,  and  then  added  to  a  mixture  of  two  parts  of  litharge, 
one  part  argol,  four  parts  soda,  and  two  parts  pulverized 
glass  to  every  eight  parts  of  dry  slag.  "The  mass  is 
thoroughly  mixed  and  then  dried  in  an  iron  or  copper  pan, 
and  melted  in  a  crucible  previously  heated  red-hot.  The 
resulting  raw  lead  is  cupelled,  yielding  brightened  silver, 
which  is  granulated  and  treated  with  aqua  regia  in  a  glass 


GOLD.  99 

cucurbit.*  After  solution,  heat  is  continued  to  expel  the 
nitric  acid ;  chlorides  of  silver  and  lead  are  filtered  off,  and 
the  gold  is  precipitated  from  the  liquid  by  iron  vitriol ;  it  is 
then  washed,  dried,  and  fused  with  saltpetre  in  a  Hessian 
crucible.  The  remaining  liquid  contains  the  platinum,  and 
is  warmed  with  iron,  thus  precipitating  various  metals ;  these 
are  boiled  with  nitric  acid,  leaving  platinum  as  a  residue. 
This  platinum  is  dissolved  in  aqua  regia,  and  extracted  by 
ammonia,  etc." 

This  method  of  extracting  gold  and  platinum,  partly  in. 
the  dry  way,  is  preferable  to  employing  the  wet  way  ex- 
clusively. 

When  re-inelting  gold  containing  osm-iridium,  the  osm- 
iridium  will  sink  to  the  bottom,  owing  to  the  great  specific 
gravity;  therefore  Californian  gold,  containing  about  0.1  per 
cent,  of  osm-iridum,  is  melted,  at  the  mints  in  Philadelphia 
and  New  York,  with  two  or  three  parts  of  silver,  thus  lessen- 
ing its  specific  gravity ;  the  specific  gravity  of  the  resulting 
gold  alloy  is  from  twelve  to  thirteen,  whilst  that  of  osm- 
iridium  is  nineteen.  On  stirring  the  fused  mass  for  some 
time  the  osm-iridium  will  settle  to  the  bottom ;  the  contents 
of  the  crucible  (8  or  10  Ibs.)  are  ladled  out  till  within  one 
inch  from  the  bottom,  and  granulated.  The  remaining 
metal,  rich  in  osm-iridium,  is  repeatedly  melted  with  silver, 
thus  concentrating  the  osm-iridium  more  and  more ;  60  Ibs. 
of  silver  are  added  at  each  of  the  last  four  or  five  meltings ; 
after  stirring,  the  mass  is  allowed  to  settle  for  some  minutes 

*  [A  flask,  sometimes  shallow,   and  with  a  wide  mouth,  or  neck.     It  must  be 
capable  of  bearing  heat.] 


100  MINERALS,   MINES,    AND   MINING. 

and  ladled  out,  leaving  10  Ibs.  of  metal  in  the  crucible,  from 
which  the  silver  is  extracted  by  sulphuric  acid,  whilst  the 
separated  gold  is  washed  out,  leaving  the  osm-iridium.  As 
gold  containing  osm-iridium  entails  more  working  expenses 
it  is  sold  at  a  cheaper  price. 

Gold  containing  osm-iridium  from  Bogoslowk  is  melted 
at  the  mint  in  St.  Petersburg,  in  a  large  plumbago  crucible ; 
the  gold  is  carefully  ladled  out  to  within  one  or  one  and  a 
half  inches  of  the  bottom,  and  the  remainder  contains  the  osm- 
iridium,  amounting  to  about  5  Ibs.  from  several  meltings. 
These  5  Ibs.  are  then  melted  in  a  small  plumbago  crucible 
with  a  narrow  bottom,  and  after  cooling  the  lower  part  of 
the  metal  regulus,  consisting  of  osm-iridium  with  a  litle  gold 
sticking  to  it,  is  cut  off;  this  gold  is  dissolved  in  aqua  regia, 
which  does  not  attack  osm-iridium. 

The  dross  resulting  from  the  treatment  of  Californian  and 
Australian  gold,  containing  gold,  silver,  and  osm-iridium,  is 
melted  with  a  reducing  and  purifying  flux  containing  litharge, 
thus  producing  raw  lead,  which  is  cupelled,  yielding  an  alloy 
from  which  the  silver  is  extracted ;  an  alloy  remaining  of 
gold  and  osm-iridium. 

According  to  d'Hennin,  the  separation  is  best  effected  by 
smelting  12.5  parts  of  dross  with  15  parts  of  black  flux,  14 
parts  of  chalk,  2.5  or  3  parts  of  arseniate  of  soda,  20  parts  of 
borax  and  carbon,  and  some  litharge  and  argol.  Auriferous 
and  argentiferous  lead  then  result,  and  on  the  top  a  mass, 
consisting  of  arsenic,  iron,  and  osm-iridium,  which  can  be 
easily  separated  from  the  lead  and  cupelled. 

Palladium  may  be  extracted  from  argentiferous  gold  by 
means  of  nitric  acid. 


GOLD.  101 

USE  or  CAST  IRON  IN  "  PARTING"  GOLD. 

The  parting  of  gold  by  means  of  sulphuric  acid  has  been 
greatly  developed  by  the  employment  of  platinum  vessels, 
though  on  account  of  their  great  expense  they  are  at  present 
but  little  used,  and  cast-iron  vessels  are  almost  universally 
employed.  Platinum  vessels  resist  perfectly  the  reaction  of 
hot  concentrated  sulphuric  acid,  but  being  very  expensive  to 
make  and  to  repair,  and  being  liable  to  considerable  waste 
from  the  friction  of  the  granulated  metal  on  their  sides,  they 
require  to  be  treated  most  carefully.  At  the  moment  when 
the  finely  divided  gold,  in  contact  with  the  platinum,  is  ex- 
posed to  the  influence  of  the  boiling  acid,  the  gold  cakes  and 
sticks  so  fast  to  the  platinum  that  it  must  be  dissolved  with 
dilute  aqua  regia,  if  slight  blows  on  the  outside  of  the  vessel 
are  not  effective.  This  operation  requires  much  dexterity. 
Above  all,  platinum  must  not  be  exposed  to  contact  .with 
lead  and  tin,  as  they  readily  alloy  with  it  at  the  temperature 
of  boiling  sulphuric  acid.  The  platinum  vessels  are  usually 
placed  in  iron  jackets  or  frames. 

At  the  mint  in  Munich,  platinum  vessels  about  9|  inches 
high,  furnished  with  a  platinum  head  5  inches  high,  and  9| 
inches  in  diameter,  were  formerly  used;  these  vessels  were 
placed  in  an  iron  frame;  at  present  iron  vessels  are  used. 
Eighty-two  and  a  half  Ibs.  of  auriferous,  silver,  containing 
about  15|  per  cent,  of  gold,  are  treated  in  three  platinum 
vessels,  each  containing  26 1  Ibs.,  with  173  Ibs.  of  concen- 
trated sulphuric  acid.  The  vessels  are  heated  first  with 
wood  and  afterwards  with  turf.  Two  and  a  half  times  as 


102  MINERALS,   MINES,   AND   MINING. 

much  sulphuric  acid  is  employed  as  there  are  silver  and  copper 
in  the  alloy.  The  heads  of  the  vesels  communicate  with  a 
leaden  tube,  partially  filled  with  water,  in  which  any  escap- 
ing sulphuric  acid  condenses.  The  surplus  sulphurous  acid 
is  conducted  into  the  chimney  by  means  of  a  leaden  tube. 

The  solution  is  finished  in  three  hours  when  some  dilute 
sulphuric  acid  of  55°  B.  is  added  to  precipitate  the  suspended 
particles  of  gold ;  after  slightly  cooling  in  a  tilting  apparatus 
the  greater  part  of  the  sulphate  of  silver  is  poured  into  a 
platinum  vessel,  leaving  the  gold  at  the  bottom. 

If  the  solution  is  not  quite  clear  it  is  reheated  with  an 
addition  of  dilute  sulphuric  acid  and  finally  poured  into  the 
leaden  precipitation  pan,  which  is  filled  to  one-third  with 
water.  The  last  auriferous  muddy  liquid  is  put  into  a 
smaller  lead  pan  and  decomposed  by  means  of  copper,  the 
resulting  silver,  alloyed  with  gold,  is  then  smelted  and  added 
to  the  next  extraction.  The  gold  remaining  in  the  solution 
vessel  is  boiled  three  or  four  times  with  sulphuric  acid,  and 
the  acid  of  the  last  boiling  is  used  for  dissolving  auriferous 
silver.  The  gold  is  washed,  dried,  and  melted  without  any 
addition  ;  the  washing  water  is  filtered  into  the  precipitation 
pan.  The  lixivium  of  silver  vitriol  is  concentrated  to  about 
25°  or  27°  B.  and  decomposed  by  copper,  100  parts  of  silver 
requiring  30  parts  of  copper-plate.  The  precipitated  silver 
is  washed,  dried,  and  melted  in  a  Hessian  crucible  standing 
within  a  plumbago  crucible  ;  some  saltpetre  is  added  to  each 
spoonful  of  charged  precipitated  silver.  The  resulting  silver 
has  usually  a  fineness  of  995.5.  The  resulting  lixivium  of 
copper  vitriol  is  concentrated  to  32°  or  3±°  B.  and  allowed 


GOLD.  103 

to  crystallize,  the  remaining  mother  liquor  is  boiled  down  to 
36°  B.  and  recrystallized,  and  the  second  mother  liquor  is 
boiled  down  to  56°  B.  in  a  leaden  pan,  and  to  66°  B.  in  a 
platinum  pan,  when  it  is  suitable  for  dissolving  auriferous 
silver. 

At  St.  Petersburg  platinum  vessels  were  formerly  used, 
four  parts  of  sulphuric  acid  were  added  to  every  three  parts 
of  silver  contained  in  the  alloy.  One  extraction  was  per- 
formed in  from  six  to  ten  hours.  The  resulting  gold  was 
boiled  once  more  with  sulphuric  acid  and  contained  when 
smelted  99.666  per  cent,  of  gold,  and  the  silver  was  of  a 
fineness  of  99.15.  Cast-iron  vessels  are  now  used  there. 

THE  DISCOVERY  OF  AND  PROVING  GOLD  ORES. 

Simple  as  the  assertion  may  seem  to  one  possessed  of  a 
merely  theoretic  knowledge,  yet  one  of  the  most  important 
and  useful  accomplishments  for  gold  exploitation,  is  "  an 
eye  for  color."  There  is  a  peculiar  color  which  native  gold 
possesses  which  is  readily  recognized,  although  that  gold 
may  be  alloyed  with  silver  or  copper,  and  its  color  will  in 
an  instant  distinguish  it  in  the  eye  of  the  expert  from  any 
condition  of  pyrites,  whether  iron  or  copper  pyrites.  This 
remark  relates  strictly  to  native  metal,  especially  as  found 
in  finely  comminuted  particles.  Nothing  but  familiarity 
with  the  metal  will  lead  to  the  possession  of  an  eye  for 
color  and  the  power  of  an  instant  recognition  of  the  metal. 

The  simplest  instrument  for  the  discovery  of  gold  in  tine 
dissemination  through  sand  or  dirt  is  a  common  iron  pan  or 


104 


MINERALS,    MINES,    AND    MINING. 


dish.  Some  dirt  is  thrown  in  and  water  poured  on  the 
whole  mass  and  by  adroit  shaking  and  by  turning  the  pan 
over  slightly  to  one  side  until  the  finer  particles  are  left  above 
the  edge  of  the  water,  the  small  particles  of  gold  are  left 
because  of  their  gravity  almost  on  the  extreme  edge  of  the 
dirt  and  will  be  instantly  recognized  by  an  "  eye  for  color." 
It  is  not  only  the  "  color,"  but  quickness  to  discover  the 
actual  presence  of  the  particle,  which  is  included  in  the  art 
of  using  the  pan,  and  we  have  known  experts  recover  con- 
siderable gold  from  pan  washings  which  had  been  by  others 
supposed  to  be  exhausted.  However,  a  certain  adroitness 
is  essential  in  handling  the  pan  by  which  some  will  expose 
every  particle  of  a  handful  of  "  pay  dirt"  in  a  few  minutes 
and  will  not  leave  two  dollars  to  the  ton.  This,  where 
water  can  be  had,  is  the  most  efficient  instrument  a  man 
can  travel  with  in  his  gold-seeking  journeys. 

Where  four  or  five  join  to  work  a  place  that  is  supposed 
to  pay,  the  cradle  or  rocker  is  more  rapid,  even  if  the  pan 

must  be  used  afterward.  There 
are  several  ways  of  putting  a  cra- 
dle together,  but  the  principle 
depends  upon  separation  of  the 
larger  barren  pieces  with  greater 
ease  and  rapidity.  Hence  the 
usual  form  is  that  of  a  long 
trough  as  represented  in  Fig.  4, 
wherein  A  is  the  handle  for  rock- 
ing the  cradle,  D  is  the  upper 
slatting  for  receiving  the  coarse 


Fig.  4. 


GOLD.  105 

dirt  and  catching  larger  stones  and  material  to  be  thrown  out 
by  hand,  B  B  the  false  bottom  which  should  be  made  movable 
and  raised  about  an  inch  or  two  above  the  true  bottom  and 
which  consists  of  slats  placed  closely  to  one  another  and 
nailed  to  a  strong  frame  so  as  to  be  removed  and  replaced 
easily.  C  C  are  the  rockers.  The  water  and  dirt  thrown 
in  at  D  are  rocked  through  to  B  B,  excepting  the  larger  peb- 
bles, etc.,  and  the  finer  pebbles  and  dirt  pass  over  the  riffle- 
bars  D  D  out  at  EE.  The  clean  sand  with  gold  will  be 
found  in  the  bottom  and  must  be  removed  as  soon  as  the 
sand  touches  the  bottom  of  the  "  riffle-bars,"  else  thin  parti- 
cles of  gold  will  be  lost. 

But  in  spite  of  all  care  much  gold  escapes  under  this 
process  and  therefore  the  sluice  system  of  washing  dirt  with 
mercury  was  introduced.  This  depends  upon  the  fact  that 
mercury  (quicksilver)  readily  amalgamates  with  gold  even 
in  the  smallest  particles.  So  a  series  of  wooden  troughs, 
all  on  an  inclined  plane,  are  made  perfectly  tight  and  occa- 
sionally fitted  with  cross-bars  made  tight  enough  to  hold 
quicksilver.  The  descending  material  holding  gold  is  some- 
what checked  at  these  little  reservoirs  of  quicksilver,  and 
the  gravity  of  the  gold  causes  it  to  come  in  contact  with  the 
metal  with  which  it  is  immediately  caught  and  the  rest  of 
the  material  passes  on.  Success  depends  upon  the  length 
of  the  line  of  troughs,  the  proper  inclination,  the  sufficient 
supply  of  water,  and  sufficient  quicksilver. 

But  sometimes  the  gold  is  so  combined  with  other  sub- 
stances, especially  sulphur,  also  arsenic  and  tellurium,  that 
the  amalgamation  is  found  difficult.  For  this  there  has 


106  MINERALS,    MINES,    AND   MINING. 

been  found  a  remedy  in  mixing  the  quicksilver  with  a  small 
per  cent,  of  sodium.  Wurtz,  of  New  York,  who  claims, 
with  Crookes,  of  London,  this  discovery,  uses  about  4  per 
cent,  of  sodium  which  combines  with  quicksilver  to  form  a 
hard  amalgam.  Crookes  uses  zinc  and  tin  as  in  the  follow- 
ing proportions:  77  quicksilver  to  3  of  sodium  and  20  of 
zinc,  and  77  quicksilver,  3  of  sodium,  10  of  zinc,  and  10  of 
tin.  Of  this  hard  amalgam  only  one  part  to  100  of  quick- 
silver, or  even  less,  is  quite  sufficient.  The  writer  has  kept 
it  in  bottles  for  months,  but  the  tendency,  if  exposed  to  the 
air,  is  partially  to  decompose,  but  even  after  partial  decom- 
position its  efficiency  is  considerable. 

When  the  quicksilver  has  been  sufficiently  loaded  with 
gold,  it  is  removed,  squeezed,  and  put  into  a  flanged  iron 
crucible,  covered  with  an  iron  cap  with  an  iron  tube  leading 
from  it,  and,  after  thoroughly  tightening,  the  end  of  the  pipe 
is  submerged  in  water  and  fire  applied  to  the  retort,  or  cru- 
cible. Great  care  must  be  taken  not  to  heat  the  crucible,  or 
retort,  beyond  the  heat  sufficent  to  volatilize  the  quicksilver, 
which  is  then  caught  in  the  water  for  use  again.  The  gold 
is  left  in  a  spongy  mass.  In  some  places  a  canvas  tube  is 
attached  to  the  end  of  the  tube  and  passes  under  the  water 
with  a  view  to  prevent  the  water  from  running  back  into 
the  retort  in  case  a  vacuum  is  formed,  but  we  have  found  no 
such  results  where  ordinary  care  has  been  taken. 

But  the  largest  quantities  of  gold  are  not  free,  but  occur 
in  the  rock  and  quartz,  and  this  requires  the  use  of  machinery 
to  crush  the  rock,  which  work  is  done  by  rollers,  stamps, 
and  mills. 


GOLD.  107 

POORER  ORES  CONTAINING  GOLD. 

But  beside  those  forms  in  which  gold  is  found,  native  or 
as  placer  gold,  and  of  which  we  have-  spoken,  there  are  other 
and  poorer  ores  in  which  the  gold  does  not  appear  to  the 
eye  as  in  the  ores  which  we  have  described. 

These  ores  are  such  as  bear  a  large  proportion  of  silver, 
tellurium,  lead,  iron,  and  copper  in  the  form  of  sulphides, 
and  they  appear  also  with  other  associations.  The  miner- 
alogist cannot  detect  the  gold  in  these  ores  without  experi- 
ments in  proving  them,  and  yet  some  of  them  are  very 
important  ores.  With  care  a  few  of  them  may  be  analyzed 
with  the  blowpipe  and  the  gold  detected,  but  even  then  the 
analyst  must  finally  resort  to  the  use  of  nitric  acid  to  separate 
the  silver,  or  to  the  use,  on  the  charcoal  base,  of  some  bone 
dust  to  absorb  the  lead  which  may  be  combined  with  the  gold. 
The  better  way  is  to  use  the  crucible  and  fuse  the  supposed 
ore  with  lead  or  litharge,  or  even  with  plumbic  sulphide 
(galena).  But  it  is  necessary,  in  some  cases,  to  concentrate 
the  ore  before  you  are  ready  to  combine  it  with  lead,  especi- 
ally if  it  be  a  lean  ore,  and  this  may  be  done  in  several  ways. 
If  it  be  an  iron,  or  pyritic  ore,  it  is  well  to  break  it  down 
into  smaller  particles  (not  powder),  and  roast  it  in  a  low  red 
heat  to  drive  off  some  of  the  sulphur.  If  the  ore  has  quartz 
in  it  which  cannot  be  separated,  it  may  be  mixed  with 
about  a  quantity  of  powdered  lime  equal  to  the  bulk  of 
quartz  and  heated,  after  the  slow  roasting.  The  lime  and 
quartz,  forming  a  slag,  allow  the  metallic  portion  to  settle  and 
concentrate,  and  when  cooled,  the  metal  and  slag  can  be 


108  MINERALS,   MINES,   AND   MINING. 

separated,  or  more  ore  and  lime  added  and  treated  as  before 
until  the  gold  in  the  ore  is  still  further  concentrated  and 
fitted  for  more  efficient  treatment  with  lead  as  above  stated. 
The  lead  then  takes  up  the  gold  and  subsides  with  it  under 
a  layer  of  ferric  sulphide. 

Where  the  ore  appears  to  be  chiefly  iron  pyrites  (FeS2) 
and  quartz,  the  crushed  ore  with  lime,  to  flux  the  quartz,  is 
fused  in  a  crucible,  when  the  pyrites  loses  half  its  sulphur 
(Fe  S),  fuses,  and  sinks  below  the  slag,  carrying  with  it  all 
the  gold.  If  this  product  be  roasted  so  as  to  convert  the  iron 
into  an  oxide,  and  be  then  again  fused  with  a  fresh  portion  of 
the  ore,  the  oxide  of  iron  will  then  flux  the  quartz  while  the 
fresh  portion  of  the  sulphide  of  iron  will  carry  down  the 
whole  of  the  gold  contained  in  both  quantities  of  ore,  and 
this  operation  may  be  repeated,  until  the  sulphide  of  iron  is 
rich  in  gold,  and  it  is  then  ready  to  be  fused  with  a  certain 
quantity  of  lead.  This  is  called  the  Hungarian  process. 

The  gold  lead  is  now  ready  to  be  cupelled,  a  work  which 
leaves  only  gold,  if  only  gold  without  any  silver  is  present. 
But  if  silver  is  also  in  the  ore,  then  the  mass,  or  "button," 
must  be  removed — flattened,  or  chipped,  so  as  to  be  more 
easily  acted  upon — placed  in  a  glass  vessel  and  treated  to 
pure  nitric  acid  which  will  dissolve  the  silver  (and  copper  if 
there  be  any),  and  leave  behind  a  dark  sediment  which,  if 
filtered  off,  washed  and  dried,  may  be  shown  to  be  metallic 
gold  in  fine  powder.  This  is  readily  done  by  either  mashing 
the  powder  upon  a  hard  smooth  surface  by  means  of  another 
hard  surface  as  that  of  a  piece  of  agate,  or  even  the  blade  of 
a  pen-knife;  or  the  powder  may  be  placed  upon  a  charcoal 


GOLD.  109 

block  with  a  little  borax  and  the  blowpipe  flame  turned 
upon  it,  when  it  will  show  its  color  as  the  particles  unite  in 
melting. 

In  the  above  we  have  to  some  degree  entered  upon  the 
work  of  the  metallurgy  of  gold,  because  the  practical  miner- 
alogist very  frequently  needs  to  test  his  ore  to  the  extent  we 
have  illustrated,  and  because  with  only  the  simple  apparatus 
suggested  he  may  satisfy  himself  sufficiently  as  to  the  value 
of  the  ore  he  has  discovered  or  has  received  from  others, 
without  entering  any  further  upon  the  more  intricate  work 
of  the  metallurgy  of  gold. 

There  are  some  precautions,  however,  which  experience  has 
taught  as  well  as  the  science  itself,  in  the  treatment  of  gold. 
It  is  necessary  that  the  nitric  acid  used  should  be  colorless, 
or,  in  other  words,  chemically  pure.  For  as  gold  is  not 
soluble  in  pure  nitric  acid,  but  always  in  the  presence  of  free 
chlorine,  any  admixture  of  the  latter  element  in  the  nitric 
acid  causes  loss  of  gold.  If,  however,  we  desire  to  dissolve 
the  gold  we  use  one-fourth  muriatic  acid  (HC1)  which  con- 
taining chlorine  (Cl)  combined  with  hydrogen,  furnishes  the 
element  for  the  purposes  in  the  nitro-muriatic  combination, 
which  therefore  in  its  best  condition  is  muriatic  acid  three 
parts,  nitric  acid  one  part,  or  one-fourth  of  the  volume  nitric 
acid. 

If  there  is  reason  for  suspicion  that  the  nitric  acid  con- 
tains any  chlorine,  a  drop  of  silver  nitrate  will  by  its  milky- 
white  precipitate  show  its  condition. 

But  another  caution  must  be  heeded  in  dissolving  an  alloy 
of  gold,  silver,  and  copper,  for  instance :  The  gold  in  the 


110  MINERALS,   MINES,   AND   MINING. 

mass  must  not  bear  too  large  a  proportion,  for  if  it  predomi- 
nates, the  action  of  the  nitric  acid  is  rendered  inefficient,  and 
hence  generally  silver  is  added  so  as  to  be  about  three  times 
that  of  the  gold,  and  this  act  of  adding  is  called  quartation. 
If,  however,  the  gold  is  known  to  be  very  small  no  further 
trouble  is  taken.  All  silver  coin  contains  gold^/and  old 
English  silver  plate  contained  so  much  gold  that  it  paid  well 
to  extract  the  gold.  With  a  fine  pair  of  scales  even  the 
gold  in  a  ten-cent  coin  may  be  detected  and  weighed. 

Another  precaution  should  be  taken  in  using  crucibles  in 
melting  gold  and  some  other  metals.  The  fine  French 
crucibles  should  always  be  used  in  preference  to  even  the 
small  Hessian,  of  both  of  which  we  have  spoken  in  the  in- 
troductory remarks  to  this  part  of  our  work.  But  even  the 
former  occasion  much  trouble  in  melting  small  quantities  of 
gold,  because  of  the  adherence  of  the  gold  to  the  sides  of  the 
crucible.  This  may  be  prevented  by  previously  dipping  the 
crucible  into  a  strong  solution  of  borax  in  water  and  drying 
the  crucible  before  use. 

In  using  nitric  acid  upon  a  mass  of  metal  containing  gold, 
if  the  mass  contains  much  silver,  the  dissolving  process  should 
be  begun  without  heat  and  the  heat  increased  slowly,  else 
there  may  be  a  sudden  commotion  which  may  cause  either 
breakage,  or  loss,  by  overflow,  since  great  heat  is  sometimes 
created  by  the  rapid  combination  of  metal  and  acid. 

In  making  assays  where  the  mass  is  to  be  dissolved  in  an 
acid,  especially  if  there  be  a  large  quantity,  it  is  well  to  pour 
the  melted  mass  into  a  vessel  containing  water ;  it  thus  be- 
comes granulated  and  is  more  readily  acted  upon  by  the  acid. 


SILVER.  Ill 


SILVER. 

SILVER.  OCCURRENT  FORM  or  APPEARANCE  IN  NATURE. 
NATIVE,  massive  and  isometric,  or  monometric — that  is, 
crystallized  in  octahedrons,  cubes  and  forms  modified  or 
altered  from  these  forms — sometimes  compressed,  or  in 
small  crystals  joined  together  in  linear  or  lateral  directions, 
sometimes  distorted.  Coarse  or  fine  thread-like,  arborescent 
— in  thin  and  irregularly  formed  plates,  in  very  fine  fissures — 
presenting,  on  edge,  the  appearance  of  minute  lines  in  very 
flint-like  or  jasper-like  rock. 

HARDNESS=2.5  to  3,  being  harder  than  gold,  but  softer 
than  copper. 

GRAVITY^IO.!  to  11.1.     When  pure,  10.5. 

COLOR,  that  of  ordinary  silver  coin,  except  where  much 
tarnished  by  contact  with  sulphur  in  vapor  or  solution,  or 
when  mixed  with  some  other  metal,  as  gold  or  copper. 
With  sulphur,  dirty  brown  or  black,  with  gold,  very  light  to 
straw  yellow,  or  pale  brass  yellow  ;  with  copper,  slight  tinge 
of  copper  red,  but  may  contain  some  copper  without  any 
apparent  change  ;  when  it  does  change  color,  it  is  more  prop- 
erly copper  with  silver. 

DUCTILITY.  Very  malleable  and  ductile,  may  be  hammered 
into  leaves  0.00001  of  an  inch  in  thickness,  and  one  grain  of 
silver  may  be  drawn  out  into  a  wire  400  feet  long.  It 
admits  of  being  welded.  (Bristow.) 

COMPOSITION.  Native  silver  occurs  in  a  state  nearer  absolute 
purity  than  is  the  case  with  native  gold,  but,  nevertheless,  it 


112  MINERALS,   MINES,   AND   MINING. 

is,  perhaps,  never  found  absolutely  pure.  (See  remarks 
under  gold.)  It  is  usually  alloyed  with  gold  and  copper. 
At  Kongsberg,  Norway,  a  yellow  alloy  is  found  which  con- 
tains silver,  with  more  than  one-fifth  of  its  weight  of  gold. 
An  amalgam  of  silver  with  mercury  is  found  in  large  quantity 
in  the  silver  mines  of  Coquimbo,  Chili.  (Bloxam.)  More 
rarely  it  has  been  found  with  platinum,  antimony,  bismuth, 
and  traces  of  arsenic.  (Dana.)  The  splendid  crystals  of 
native  silver  found  at  Kongsberg,  Norway,  are  supposed  to 
owe  their  beauty,  in  some  measure,  to  the  presence  of  a  small 
amount  of  mercury.  (Scemann.)  It  sometimes  contains  as 
much  as  3  per  cent,  of  antimony,  arsenic,  and  iron,  and  is 
sometimes  associated  with  grey  copper  ores.  (Authorities  in 
Crooks  and  Rohrig.) 

LOCALITIES,  GEOLOGY,  and  ASSOCIATIONS. 

It  occurs  in  masses  and  in  veins  traversing  gneiss,  schist, 
porphyry,  and  other  rocks. 

Kongsberg  silver  mine,  Norway,  43  miles  W.  S.  W.  of 
Christiania,  which  was  discovered  in  1623,  is  the  most  im- 
portant in  the  kingdom,  and,  though  nearly  abandoned  in 
1805,  was  again  worked  in  1816,  and  is  nourishing  since 
1830.  The  region  immediately  around  this  mine  is  gneiss 
and  mica-schist,  and  between  the  Cambrian  on  the  west 
and  lower  Silurian  on  the  east.  (Dumont.) 

From  this  mine  several  very  large  masses  of  silver  have 
been  taken;  one  weighing  more  than  5  cwt.,  and  more 
recently  (1868),  two,  one  weighing  238  and  the  other  436 
pounds.  One  specimen  from  Southern  Peru,  mines  of 
Huantaya,  weighed  over  8  cwt.  But  all  these  are  surpassed 


SILVER.  113 

by  one  "mass  discovered  in  Sonora,  which  Wilson  states 
weighed  2700  pounds  and  was  the  subject  of  a  suit  brought 
on  behalf  of  the  king,  who  thought  to  recover  it  on  the  plea 
that  it  was  a  curiosity,  and  belonged  to  the  Crown."  (Lam- 
born,  Metallur.  Silver,  p.  52.) 

In  the  United  States,  in  Michigan,  Lake  Superior,  in  1873, 
in  masses  of  several  pounds  weight,  perfectly  free  from  all 
other  metals ;  also  with  the  copper  of  Lake  Superior  copper 
mines ;  also  with  silver  sulphides  on  the  northern  shore  at 
Silver  Inlet,  and  at  the  latter  place  with  galena  most  inti- 
mately mixed  in  one  mass  at  the  Chicago  Exposition,  1873, 
and  weighing,  perhaps,  forty  pounds.  Near  Ontanagon  in 
films  in  sandstone;  Dana  (mineralogy)  says  that  it  has  been 
observed  at  a  mine  a  mile  south  of  Sing  Sing  Prison ;  at  the 
Bridgewater  copper  mines,  New  Jersey ;  in  interesting 
specimens  at  King's  mine,  Davidson  Co.,  North  Carolina  ; 
rarely  in  filaments  with  barytes  at  Cheshire,  Conn.  In  Idaho, 
at  the  "  Poor  Man's  lode,"  large  masses  of  native  silver  have 
been  obtained ;  rarely  in  the  Com  stock  lode  and  mostly  in 
filaments,  and  rarely  in  the  Ophir  mines ;  in  California, 
sparingly  in  Silver  Mountain  district,  Alpine  Co. ;  in  the 
Maris  vein,  in  Los  Angeles  Co. 

Native  silver  generally  occurs  in  veins  of  calcareous  spar, 
or  quartz,  traversing  gneiss,  slate,  and  others  of  the  older 
rocks.  (Bristow.)  It  may  also  be  invisibly  disseminated 
through  native  copper. 

Many  have  been  deceived  by  a  mineral  called  arsenical 
iron  or  mispickel,  which  has  a  silvery  appearance  and  is 
found  in  quartz  and  other  mineral  associations.  Near  Mid- 

8 


114  MINERALS,    MINES,    AND    MINING. 

dletown,  Conn.,  some  money  was  wasted  several  years  ago 
upon  a  place  where  it  occurred  and  it  has  caused  much  de- 
ception elsewhere.  This  ore,  mispickel,  may  be  distinguished 
from  native  silver  by  its  brittleness  and  the  arsenical  fumes 
it  gives  off  under  the  blowpipe,  when  it  turns  black  and  is 
attractable  by  the  magnet,  showing  its  composition  as  iron. 
The  scent  of  the  fumes  of  arsenic  is  somewhat  like  that  of 
onions. 

The  principal  ores  of  silver  do  not  resemble  silver,  but 
contain  in  varying  quantities  lead  with  other  associations, 
but  in  smaller  quantity  than  that  of  the  lead.  Almost  all 
galena  (lead  sulphide)  contains  silver  sometimes  in  very 
small  quantities.  Some  of  the  lead  ores  in  Southern  Indiana, 
Rosa  Clare  mines,  contain  scarcely  a  trace  of  silver,  and  the 
same  may  be  said  of  some  near  Lexington,  Ky.  Generally 
speaking,  the  lead  ores  which  present  a  grain  or  rough  ap- 
pearance contain  silver,  while  those  which  have  shining  sur- 
faces contain  less,  but  this  is  not  always  true.  The  separa- 
tion of  silver  from  galena  will  be  spoken  of  under  lead. 

Copper  ores  contain,  sometimes,  much  silver,  and  the  sepa- 
ration of  silver  from  copper  is  described  under  copper. 

Several  minerals  rich  in  silver  may  be  found,  which, 
while  they  indicate  silver,  are  not  usually  considered  true 
ores  in  this  country.  Of  these  the  following  are  worthy  of 
mention,  as  indicating  the  neighborhood  of  true  ores  : — 

ANTIMONIAL  SILVER,  or  DYSCRACITE;  foreign  specimens 
contain  about  75  to  80  per  cent,  silver,  and  20  to  25  anti- 
mony. Hardness,  3.5  to  4.  Gravity,  9.4  to  9.8.  Color 
and  streak  silver  white,  sometimes  tarnished.  Opaque. 


SILVER.  115 

Before  the  blowpipe  fuses  on  charcoal,  coating  the  edges 
of  the  charcoal  around  the  assay  with  antimonial  white 
oxide  and  finally  giving  a  globule  of  silver.  The  bead  is 
soluble  in  nitric  acid  leaving  oxide  of  antimony. 

BISMUTH  SILVER  also  occurs  in  foreign  localities  with  86  per 
cent,  silver  and  14  per  cent,  bismuth.  It  is  soft,  silver  white, 
tarnishes  easily,  and  easily  shows  silver  under  the  blowpipe. 

FREIESLEBENITE  is  the  mineralogical  name  given  to  a  light 
steel  gray,  or  inclining  to  silver- white,  mineral.  H.  2.  to  2.5, 
gravity  6  to  6.4,  yields  easily  to  the  knife  and  rather  brittle. 
Streak  same  as  color.  Composition,  when  pure,  sulphur 
18.6,  Sb  25.9,  lead  31.2,  silver  24.3. 

Before  the  blowpipe  in  an  open  tube  it  yields  both  sulphur- 
ous and  antimonial  fumes,  the  latter  condensing  upon  the 
sides  as  a  white  sublimate.  On  charcoal  fuses  easily,  giving, 
outside,  white  of  the  antimonious  acid,  and  nearer,  the  yellow 
oxide  of  lead.  After  a  time  the  silver  globule  appears. 

STEPHANITE  is  an  ore  and  found  and  worked  in  Nevada, 
Idaho,  and  elsewhere.  Found  massive  and  disseminated. 
H.  2.  to  2.5;  gravity,  6.3.  Has  a  metallic  lustre,  but  streak 
and  color  iron-black.  S  16.2,  Sb  15.3,  silver  68.5  =  100. 
It  rarely  contains  traces  of  Fe  and  Cu.  It  is  soluble  in  di- 
lute heated  nitric  acid  with  precipitation  of  sulphur. 

Before  the  blowpipe  acts  as  in  the  last-mentioned  mineral 
except  that  after  long  blowing  a  red  color  appears  upon  the 
antimonial  coloring,  on  the  charcoal,  from  the  oxidized  silver. 

ARGENTITE  is  a  sulphide  of  silver.  H.  2.  to  2.5;  grav.,  7.2 
to  7.3.  Lustre  metallic,  streak  and  color  blackish  lead-gray, 
but  streak  shining.  Opaque,  readily  cut  with  a  knife. 


116  MINERALS,   MINES,   AND   MINING. 

Composition  S  12.9,  silver  87.1  =  100,  but  generally  less 
silver.  It  occurs  in  Nevada  and  some  other  mines  with 
stephanite  and  is  an  ore. 

RUBY  SILVER,  or  PYRARGYRITE,  is  an  antimonious  sulphur 
silver,  sometimes  found  in  large  masses,  one  in  Idaho,  Poor- 
man's  lode,  weighing  several  hundred  weight.  H.  2.  to  2.5  ; 
grav.,  5.7  to  5.9,  lustre  metallic,  color  from  black  to  carmine 
red,  streak  red,  translucent  to  opaque.  Composition  S  17.7, 
Sb  22.5,  silver  59.8  =  100,  specimen  in  possession  of  the 
author  about  57  per  cent,  silver,  from  Mexico. 

It  appears  then  from  the  preceding  that  silver  when  not 
native  is  generally  found  associated  with  S,  Sb,  Pb,  Bi,  and 
it  is  the  desire  of  the  assayer  at  first  to  separate  the  silver  as 
the  most  important  element. 

THE  DRY  WAY.  Cupellation  is  the  process  used.  This  we 
have  described  in  the  introduction  to  this  part  of  our  work. 
But  there  is  a  preliminary  assay  with  the  ore,  the  object  of 
which  is  to  form  an  alloy  of  the  silver  contained  in  the  ore 
with  lead,  which  is  to  be  added  generally  as  litharge. 

The  process  as  described  by  Makins  is  the  simplest  and  is 
as  follows :  As  it  is  best  to  have  no  more  lead  for  the  subse- 
quent cupel  operation  than  is  absolutely  necessary,  the  flux- 
ing with  litharge  is  an  operation  requiring  much  care,  since 
the  ore  itself  is  apt  to  vary  very  much  in  its  effect  upon  the 
litharge^  and  so  render  different  and  opposite  modes  of  treat- 
ment necessary.  For  example,  most  ores  contain  sulphur 
or  other  bodies  which  have  a  strong  affinity  for  oxygen, 
hence  such  ores  would  very  readily  reduce  the  litharge. 
Therefore,  in  order  to  prevent  this  from  taking  place  to  too 


SILVER.  117 

great  an  extent,  it  is  found  necessary  to  add  also  an  oxidiz- 
ing flux,  as  nitre  (potassium  nitrate),  to  counteract  in  a  suffi- 
cient degree  the  reducing  power  of  the  ore.  Then,  on  the 
other  hand,  the  ore  may  naturally  be  of  an  oxidizing  char- 
acter, in  which  case  not  only  will  no  oxidizing  flux  be 
required,  but,  on  the  contrary,  a  reducing  one,  such  as  argol 
(coarse  bitartrate  of  potass),  must  be  used ;  while,  lastly, 
the  ore  may  chance  to  possess  just  the  reducing  power 
requisite  to  act  sufficiently  upon  the  litharge  and  no  more, 
in  which  case  the  litharge  alone  is  employed. 

From  all  this  it  will  be  seen  that  the  first  step  required 
in  the  assay  of  a  silver  ore  is  one  whereby  we  may  learn  its 
nature  in  the  above-mentioned  respects.  For  this  purpose 
Mitchell  advises  a  preliminary  assay  upon  about  twenty 
grains  of  ore,  which  is  to  be  powdered  and  mixed  intimately 
with  five  hundred  of  litharge.  This  mixture  is  put  into  a 
small  crucible,  capable  of  containing  about  double  the  bulk, 
the  crucible  is  heated  very  gently  at  first,  but  after  a  time 
the  heat  is  to  be  quickly  raised  to  a  full  red  so  as  to  com- 
plete the  operation  as  speedily  as  possible.  When  cool  the 
pot  is  broken,  and  the  button  removed  and  weighed.  It 
may  be  that  but  little  lead  has  been  reduced,  perhaps  not 
more  than  half  the  weight  of  the  ore  used.  In  such  a  case 
an  actual  assay  would  be  made  of  the  following  mixture : 
200  grains  of  ore,  200  of  sodic  carbonate,  1000  of  litharge, 
and  15  grains  of  argol,  for  the  purpose  of  assisting  the  re- 
duction of  the  lead.  Secondly,  if  the  trial  button  should 
weigh  about  double  the  weight  of  ore  employed  then  the 
same  mixture  should  be  used,  except  as  regards  the  argol, 


118  MINERALS,    MINES,    AND    MINING. 

which  mnst  be  omitted  and  about  fifty  grains  of  nitre  be 
used  in  its  place.  Thirdly,  if  the  trial  button  weighed 
about  the  same  as  the  ore  then  litharge  alone  would  be  em- 
ployed without  either  reducing  or  oxidizing  flux. 

The  mixture  being  intimately  made  as  above  is  to  be  put 
into  a  proper  sized  crucible,  and  it  may  be  here  observed 
that  in  all  cases  where  nitre  is  employed,  either  in  assaying 
or  melting  operations,  a  very  capacious  crucible  should  be 
taken,  as  considerable  action  is  always  set  up.  The  mixture 
is  next  covered  with  a  layer  of  salt  (sodium  chloride)  and 
lastly  with  200  grains  of  powdered  borax.  The  crucible  is 
put  into  the  furnace  and  the  gentle  heat  at  first  used  raised 
until  the  fluxes  are  thoroughly  liquid,  at  which  point  the 
assay  will  be  found  completed.  The  pot  is  then  removed 
and  when  cool  broken,  the  button  hammered  so  as  to  sepa- 
rate all  the  flux,  and  reserved  for  subsequent  cupellation. 

There  is  another  operation  which  is  applicable  in  all 
cases,  especially  where  the  assay  is  one  of  shop  sweepings 
containing  solder  and  even  zinc  and  tin,  and  hence  appli- 
cable to  almost  any  ore  of  similar  composition.  It  has  the 
name  of  scorification  and  precedes  the  work  of  cupellation. 
It  consists  in  heating  the  specimen  under  examination  with 
a  quantity  of  granulated  lead  in  a  shallow  clay  vessel  or 
"  scorifier,"  the  name  given  it  in  the  chemical  warehouse. 
The  operation,  as  given  by  Makins,  is  as  follows:  The  scori- 
fier is  so  placed  in  a  muffle  as  that  a  current  of  atmospheric 
air  may  pass  over  the  surface  of  the  vessel  and  oxidize  por- 
tions of  the  lead.  This  oxide  of  lead  then  forms  a  men- 
struum for  the  suspension  of  foreign  matters  and  combines 


SILVER.  119 

with  silica  as  a  fusible  slag,  while  the  portion  kept  unoxi- 
dized  will  retain  the  gold  and  silver  sought  for  in  the  sample. 
The  operation  is  carried  on  as  follows :  A  quantity  of 
about  fifty  grains  of  the  sample  is  weighed  and  powdered ; 
this  will  be  about  the  quantity  workable  in  one  scorifier,  but 
it  is  advisable  to  work  this  as  in  all  assays  double,  hence  two 
scorifiers  are  prepared.  A  quantity  of  granulated  lead  is 
next  taken  and  the  amount  required  may  range  from  twelve 
to  thirty  times  the  weight  of  the  ore  or  of  the  sweepings. 
The  quantity  required  will  be  large  if  much  tin  or  zinc  be 
present,  or  if  (as  in  the  case  of  an  ore)  it  contain  a  large 
proportion  of  lime  salts.  Half  this  amount  of  lead  is  first 
put  into  each  scorifier  and  upon  it  the  50  grains  of  the 
specimen  previously  mixed  with  50  of  borax.  The  whole 
is  then  mixed  and  covered  with  the  remaining  half  of  lead. 
The  scorifiers  are  then  placed  in  a  heated  muffle  and  the 
opening  closed  up  for  a  quarter  of  an  hour  so  as  to  fuse  the 
lead.  The  heat  is  then  allowed  to  fall,  the  door  of  the 
muffle  opened  as  in  carrying  on  a  cupellation,  and  the 
roasting  of  the  mass  commenced.  A  slag  will  form  first  at 
edges  of  the  bath  and  increase  over  the  surface,  but  as  the 
lead  oxidizes  it  becomes  quite  fluid ;  the  whole  should  be 
now  occasionally  stirred  so  as  to  keep  all  parts  mixed.  The 
heat  is  then  raised,  whereby  the  whole  is  rendered  fully 
liquid.  This  last  fact  may  be  judged  of  by  the  facility  with 
which  it  runs  off  an  iron  stirrer  which  is  crooked  at  the  end 
so  as  conveniently  to  be  dipped  into  the  bath.  Thus  under 
the  influence  of  the  borax  the  metallic  particles  are  so 
cleansed  as  to  run  well  together,  the  borax  assisting  also  in 


120  MINERALS,    MINES,    AND   MINING.  , 

the  formation  of  a  liquid  slag  from  the  first.  The  assay 
being  in  this  limpid  state  at  the  end  of  the  operation  (which 
will  be  completed  at  the  end  of  half  an  hour  to  three- 
quarters)  the  scorifier  is  removed  and  its  contents  poured 
quickly  into  a  hemispherical  iron  ingot-mould.  Thus  a 
button  is  obtained,  consisting  of  a  greenish  slag  at  the  top, 
covering  a  button  of  metal ;  these  are  to  be  separated  by  a 
blow  of  the  hammer  and  the  metal  reserved  for  cupellation 
and  "  parting"  for  gold. 

If  the  operation  has  been  well  performed,  this  button  will 
be  tolerably  malleable,  and  the  slag  quite  free  from  any 
beads  of  metal.  If  these  features  be  not  present  the  assay 
is  not  trustworthy.  The  working  may  be  divided  into  three 
stages,  namely,  of  about  a  quarter  of  an  hour  for  the  first 
fusion ;  next  twenty  minutes  for  the  roasting  and  oxidiza- 
tion ;  and  lastly,  ten  minutes  for  the  final  fusion  of  the 
whole. 

The  next  process  is  that  of  cupellation.  This  depends 
upon  the  property  which  characterizes  the  noble  metals, 
namely,  that  w*hen  heated  to  fusion,  and  exposed  to  a 
current  of  air,  not  the  least  oxidation  takes  place,  while 
such  treatment  of  base  metals  constituting  alloys,  under 
certain  conditions,  perfectly  oxidizes  them.  So  that  by  this 
means  alone  we  are  able  to  get  rid  of  the  alloy  associated 
with  a  precious  metal,  platinum  excepted.  (  See  under  Lead.) 

The  buttons  are  now  ready  for  cupellation,  which  process 
we  have  described.  In  addition  to  what  we  have  already 
said,  we  may  say  that  charcoal,  coke,  or  anthracite  may  be 
used,  charcoal  for  a  small  furnace,  coke  and  anthracite  for  a 


SILVER.  121 

larger  one.  The  objectionable  feature  in  some  otherwise 
very  well  arranged  cupel  furnaces  is  that  the  furnace  is  too 
thin  in  front  and  the  heat  becomes  disagreeably  great.  If 
the  front  is  built  with  two  bricks  and  the  sides  with  one 
brick  thickness,  the  furnace  heat  is  more  endurable.  Care 
must  be  taken  to  have  a  draft  sufficiently  strong  and  a 
damper  in  the  pipe,  if  a  stove  is  used,  or  a  sliding  cut-off  in 
the  chimjiey  if  the  furnace  connects  with  the  chimney 
directly.  The  muffle  should  have  a  well  fitting  piece  of 
brick  (fire  brick)  stopper  to  correct  or  stop  entirely  the  draft 
passing  from  the  front  of  the  muffle  over  the  assay  when,  as 
in  this  case  stated  above,  it  is  better  to  stop  for  a  season  all 
draft  through  the  muffle.  (/See  the  drawing  already  given.) 

Caution.  It  has  been  found  that  when  the  silver  is 
worked  with  less  than  three  times  its  weight  of  lead  the 
result  is  not  trustworthy,  and  Makins  says  that  the  English 
standard  requires  six  times  its  weight.  Hence  we  should 
exceed  the  three  times  rather  than  attempt  to  equal  it. 

The  fusible  lead  oxide  readily  gives  up  a  part  of  its 
oxygen  to  any  copper  oxide  which  is  also  formed,  and  this 
cupric  oxide  is  dissolved  in  the  fluid  litharge  and  passes 
with  it  into  the  porous  cupel  in  which  the  assay  is  made. 
Tin  or  antimony  or  any  volatile  metal,  or  substance,  has 
been  probably  entirely  driven  off  in  the  scorification  and 
finally  almost  entirely  disappears.  Unfortunately  the  dry 
processes  are  usually  attended  with  some  loss  of  silver, 
sometimes  very  minute  and,  perhaps  for  some  purposes, 
unimportant,  but  nevertheless  for  very  accurate  results  we 
must  resort  to  the — 


122  MINERALS,    MINES,    AND    MINING. 

WET  PROCESS,  or  humid  assay  of  silver.  A  process  of 
separating  silver  from  copper  is  that  of  Haidlen  and  Fre- 
senius,  namely:  Add  cyanide  of  potassium  to  the  solution  of 
the  two  metals  until  the  precipitate  redissolves.  A  current 
of  sulphuretted  hydrogen  is  then  passed  into  the  liquor,  the 
excess  of  gas  expelled  by  heat  and  a  little  more  cyanide 
added.  The  silver  is  thus  precipitated  while  the  copper 
remains  in  solution. 

Another  method  where  gold  is  in  association  is  as  follows  : 
Dissolve  the  argentiferous  copper  in  sulphuric  acid  and  pre- 
cipitate the  silver  from  the  solution  by  introducing  clean 
slips  of  copper ;  the  precipitated  silver,  which  is  in  the  form 
of  a  gray  metallic  powder,  is  washed  and  fused  in  a  clay 
crucible  with  a  mixture  of  nitrate  of  potassium  and  borax ; 
it  is  thus  purified  from  the  copper  which  may  have  been 
precipitated  with  it.  The  copper  may  for  the  arts  be  recov- 
ered by  crystallization  as  cupric  sulphate  (blue  vitriol),  and 
the  gold  having  remained  in  the  solution,  undissolved  in  the 
sulphuric  acid,  can  be  filtered  therefrom,  before  crystallizing 
the  copper  sulphate.  This  method  is  used  where  the  silver 
and  gold  only  are  required  very  nearly  accurately  and  the 
copper  "by.  difference"  by  subtracting  the  weights  of  the 
gold  and  silver  from  the  weighed  argentiferous  copper  used 
at  the  beginning.  But  this  process  is  not  as  accurate  as 
may  be  required.  In  that  case  the  specimen  may  be  dis- 
solved in  nitric  acid  and  the  silver  chloride  precipitated  by 
hydrochloric  acid,  as  we  have  elsewhere  shown,  filtered, 
washed,  and  weighed  after  the  chloride  has  been  reduced  by 


SILVER.  123 

hydrogen  (see  under  Reagents  "  silver  nitrate),  and  the 
copper  determined  by  difference. 

Caution. — Rose  has  shown  that  some  traces  of  silver  are 
dissolved  in  chlorides  of  potassium,  sodium,  and  ammonium, 
and  therefore  it  is  not  well  to  precipitate  silver  by  these  salts, 
but  when  it  has  been  so  precipitated  it  is  recommended  (by 
Gay  Lussac  and  Liebig)  to  evaporate  the  solution,  filtered 
from  the  chloride  of  silver,  nearly  to  dryness,  and  to  treat 
the  residue  with  nitric  acid ;  on  exposing  the  whole  to  heat, 
the  alkaline  chlorides  are  converted  into  nitrates,  while  the 
small  quantity  of  silver  chloride  remains  unaltered,  and  does 
not  dissolve  when  the  mixture  is  diluted.  Silver  is  sepa- 
rated from  all  the  metals  of  the  first  four  groups  (see  at  the 
beginning  of  this  part)  by  sulphuretted  hydrogen  from  acid 
solutions.  From  lead  it  may  be  separated  by  hydrochloric 
acid,  the  solution  having  been  previously  diluted  largely  to 
prevent  the  precipitation  of  chloride  of  lead,  or  by  heating 
the  solution  containing  both  metals  with  cyanide  of  potas- 
sium which  precipitates  the  lead  in  the  state  of  carbonate, 
retaining  the  silver  in  solution,  as  argento-cyariide  of  potas- 
sium. The  silver  is  subsequently  precipitated  in  the  form  of 
cyanide  of  silver  by  the  addition  of  nitric  acid. 

To  separate  SILVER  from  LEAD  the  precipitation  is  advan- 
tageously preceded  by  addition  of  sodium  acetate.  The  fluid 
must  be  hot  and  the  hydrochloric  acid  rather  dilute  and  no 
more  added  of  the  latter  than  is  just  necessary.  In  this 
manner  the  separation  may  be  readily  effected,  since  lead 
chloride  dissolves  in  sodium  acetate.  The  silver  chloride  is 
washed  with  hot  water.  The  lead  is  thrown  down  from  the 


124  MINERALS,   MINES,    AND   MINING. 

filtrate  by  hydrogen  sulphide.  Great  care  must  be  taken  in 
washing  the  silver  chloride  from  all  sodium  acetate. 

SILVER  is  separated  from  cadmium  and  bismuth  com- 
pounds, thus:  Add  to  the  nitric  acid  solution  containing  ex- 
cess of  nitric  acid  hydrochloric  acid  as  long  as  a  precipitate 
forms,  and  separate  the  precipitated  silver  chloride  from  the 
solution  which  contains  the  other  metals  by  introducing  a 
strip  of  zinc,  or  iron,  and  add  some  dilute  sulphuric  acid. 
Wash  the  spongy  silver  first  with  dilute  sulphuric  acid,  then 
with  water,  and  finally  dissolve  it  in  nitric  acid.  It  may 
now  be  precipitated  with  hydrochloric  acid  and  be  determined 
(weighed)  as  chloride,  or  by  reducing  with  zinc  to  silver, 
washed  and  dried,  be  weighed  as  silver,  as  we  have  already 
shown.  (See  under  "  Reagents"  for  silver  chloride  reduced 
to  silver  by  zinc.) 

SILVER  from  MERCURY  requires  that  the  nitric  acid  solution, 
or  rather  the  silver  nitrate  in  solution  should  have  an  addi- 
tion of  acetate  of  sodium.  But  to  be  sure  of  complete  sepa- 
ration of  the  silver,  mix  the  nitric  acid  solution  (free  from  any 
mcrcurous  salt  and  acidified  with  nitric  acid)  with  sufficient 
water,  and  with  hydrochloric  acid  so  long  as  any  precipitate 
falls.  Filter  and  heat  the  precipitate  with  a  little  nitric  acid, 
add  a  little  water,  then  a  few  drops  of  hydrochloric  acid  and 
filter  off  the  silver  chloride.  This  is  done  lest  any  mercuric 
salt  was  precipitated  with  the  silver.  In  the  filtrate  the 
mercuric  solution  remains  which  must  be  determined  as  sul- 
phide by  diluting  sufficiently,  acidulating  with  hydrochloric 
acid  and  precipitating  with  clear  saturated  hydrogen  sulphide 
water,  or  (in  the  case  of  large  quantities)  by  passing  through 


COPPER.  1  '25 

it  the  gas.  Filter  quickly  after  allowing  a  partial  deposit, 
wash  with  cold  water,  dry  at  the  heat  of  boiling  water,  and 
weigh.  The  proportions  are  as  follows: — 

Hg  200  86.21  per  cent. 

S  32  13.79    "      « 


232  100.00    "      " 

SILVER  from  STJLPHURETS.  In  assaying  the  sulphurets,  the 
finely  pulverized  ore  must  be  acted  upon  by  strong  nitric 
acid  as  in  the  case  of  lead  sulphuret.  (See  under  Copper 
Sulphides  for  another  process.) 


COPPER. 

The  useful  copper  minerals  may  be  divided  into  three 
classes,  the  native  copper  ores,  the  compound  copper  ores, 
and  ores  not  strictly  copper  ores  but  ores  from  which  in  ob- 
taining other  metals,  copper,  as  matter  of  economy,  is  ex- 
tracted. 

NATIVE  COPPER,  as  a  true  ore,  occurs  in  the  United  States 
most  extensively  in  the  Lake  Superior  copper  region  near 
Keweenaw  Point.  One  mass  weighing  420  tons  was  dis- 
covered in  1857  in  the  Minnesota  mine  in  the  belt  of  con- 
glomerate, which  forms  the  foot-wall  of  the  vein.  (Dana.) 
But  it  has  been  found  in  New  Jersey,  Connecticut,  Califor- 
nia, and  Arizona ;  compound  and  native  in  Montana,  New 
Mexico,  Colorado,  Utah,  Wyoming,  Nevada,  Idaho.  Mis- 
souri, and  elsewhere. 


126  MINERALS,    MINES,    AND    MINING. 

It  is  almost  always  associated  with  silver,  sometimes  with 
bismuth  and  other  metals. 

HARDNESS,  2.5  to  3;  gravity,  8.8  to  8.9,  in  the  best 
native  ore. 

BEFORE  THE  BLOWPIPE  it  fuses  easily ;  on  cooling  becomes 
covered  with  a  coat  of  black  oxide.  Dissolves  readily  in 
nitric  acid  giving  off  red  fumes.  Easily  distinguished  by 
its  color. 

ITS  GEOLOGICAL  POSITION  varies.  In  Eastern  United  States 
it  is  found  in  the  red  sandstone,  in  Lake  Superior  region  in 
the  Silurian  trap  rocks,  in  Texas  in  the  granite,  in  quartz 
rocks,  as  reported  ;  its  locality  is  generally  among  the  earlier 
formations. 

The  usual  compound  ores  of  copper  are  chiefly  COPPER 
PYRITES,  from  which  the  larger  part  of  the  copper  in  Great 
Britain  is  obtained.  Its  composition  is  Cu2  S,  Fe2  S3,  and 
contains,  when  pure,  34.4  per  cent,  copper,  but,  due  to  im- 
purities, it  may  not  hold  more  than  ten  or  twelve  per  cent. 
COLOR,  brassy;  gravity,  4.2.  LOCALITY,  in  the  primitive 
rock,  and  especially  in  clay  slate. 

Another  sulphide  is  worked,  called  purple  ore,  or  varie- 
gated ore,  whose  composition  varies  but  is  generally  Cu2  S, 
FeS2  with  56  per  cent,  of  copper. 

There  is  another  ore  also  a  sulphide,  called  indigo  copper. 
This  contains  66  per  cent,  copper,  but  although  specimens 
are  found  in  some  places  it  does  not  occur  extensively  as  an 
ore. 

Other  ores  with  less  copper  may  be  worked  and  may  be 
valuable. 


COPPER.  127 

BLOWPIPE  AND  OTHER  DETECTION  OF  COPPER.  Heated  in 
the  blowpipe  oxidizing  flame  it  will  generally  produce  a 
greenish  tinge  to  the  flame.  With  borax  a  green  bead  is 
formed  which  becomes  blue  when  cold.  In  the  reducing 
flame  the  bead  will  be  reddish  when  cold.  If  heated  upon 
charcoal  with  soda  carbonate  in  the  reducing  flame  we  get 
a  bead  of  metallic  copper,  if  not  too  much  mixed  with  im- 
purities. 

Copper  may  be  detected  in  exceedingly  weak  solutions  by 
placing  a  drop  of  the  suspected  solution  upon  a  strip  of  clean 
platinum  foil.  If  now  a  point  of  zinc  be  placed  in  the  solu- 
tion, but  touching  the  foil,  a  spot  of  reduced  copper  will  be 
seen,  if  present,  at  the  point  of  contact. 

The  blue  reaction  which  copper  ores,  when  roasted,  or 
calcined,  in  a  little  crucible,  or  in  fragments,  under  the 
blowpipe,  with  carbonate  of  soda,  give  with  ammonia,  always 
indicates  the  presence  of  copper,  and  after  the  discovery  that 
the  ore  contains  copper  we  proceed  to  ascertain  the  quan- 
tity. 

BY  DRY  METHOD.  This  method  never  will  yield  all  the 
copper  accurately,  but  it  is  so  nearly  the  kind  of  copper  pro- 
duced by  the  smelting  works  before  it  is  entirely  refined, 
that  it  is  preferred  as  an  assay  by  some,  and  is  as  follows : 
Take  about  two  or  three  hundred  grains,  but  if  lean,  as  an 
ore,  take  more.  The  weighed  quantity  is  mixed  with  about 
twice  its  weight  of  a  flux  composed  of  equal  weights  of  Iime9 
borax,  powdered  glass,  and  fluorspar.  The  mixture  is  put 
into  a  crucible  and  heated  to  fusion,  tapped  down  so  as  to 
cause  all  particles  to  conglomerate  in  the  bottom  of  the  cm- 


128  MINERALS,    MINES,   AND   MINING. 

cible.  The  whole  is  then  poured  into  any  iron  mould,  and 
as  soon  as  set  the  whole  is  plunged  into  water,  thus  crack- 
ing off  the  glassy  slag.  The  brittle  "  regulus"  is  then  pow- 
dered, roasted  without  allowing  it  to  fuse,  but  stirring  to  get 
rid  of  all  volatile  matter  as  far  as  possible.  When  well 
roasted  the  residue  is  put  into  a  crucible  and  mixed  with  a 
flux  composed  of  argol,  nitre  (saltpetre),  and  borax  ;  the  cru- 
cible is  now  heated  till  the  copper  subsides  beneath  the  slag. 
The  button  may  be  a  little  coarse  but  it  can  be  refined  to 
some  degree  by  throwing  it  into  a  red  hot  crucible  and  heat- 
ing with  some  flux  of  lime  and  powdered  common  porcelain, 
or  powdered  china,  in  the  proportion  of  two- thirds  weight  of 
the  former  and  one  third  of  the  latter,  in  a  sufficient  quan- 
tity to  cover  the  button  a  half  inch  deep.  Heat  to  melting 
for  ten  to  twenty  minutes,  cool  and  remove  and  weigh. 

THE  WET  METHOD.  If  the  solution  contains  only  copper  or 
no  other  metal  whose  oxide  is  thrown  down  by  potassa,  we 
have  only  to  add  an  excess  of  caustic  potassa,  or  soda,  and 
well  boil  the  precipitate  (oxide  of  copper),  wash,  dry,  and 
weigh.  The  precipitate  (which  is  cupric  oxide)  contains 
79.85  per  cent,  metallic  copper. 

CAUTION.  The  solution  should  be  dilute  and  the  precipi- 
tate well  washed  with  boiling  water,  or  some  potassa  will 
adhere.  If  any  organic  matter  is  in  the  solution  it  will  de- 
teriorate results,  or  if  any  organic  acids  are  used  or  have  been 
in  the  solution,  another  process  must  be  adopted,  or  organic 
matter,  if  any  was  in  the  ore,  must  be  burned  out  by  roast- 
ing or  by  continued  red  heat.  The  cupric  oxide  thus  formed 
is  a  brownish  black,  or  black  precipitate. 


COPPER.  129 

If  silver  be  present  with  the  copper,  it  is  precipitated  from 
a  nitro  hydrochloric  acid  solution  by  sodium  chloride  as  we 
have  described  under  SILVER,  and  the  copper  in  the  blue 
solution  of  copper  precipitated  as  oxide,  as  above  stated. 

THE  COPPER  SULPHIDES,  as  in  many  other  metallic  sulphides, 
may  be  decomposed  and  sulphur  separated  thus :  The  sulphur 
is  determined  as  sulphuric  acid  (H2  O  S  O4) ;  pulverize  the 
metallic  sulphide,  weigh  and  place  it  in  a  test  tube.  Have 
a  flask  with  sufficient  fuming  nitric  acid  in  it  to  dissolve  all 
the  pulverised  sulphide  ;  slip  the  test  tube  into  the  flask  and 
immediately  cover  the  end  with  a  loose  glass  stopper  during 
the  commotion  of  the  dissolving  powder,  wait  till  quiet,  and 
then  agitate  the  assay  till  all  is  dissolved  and  the  fuming  gas 
is  absorbed ;  wash  off  the  glass  stopper  with  a  few  drops  of  ni- 
tric acid  into  the  flask,  heat  gently  ;  the  whole  of  the  sulphur 
is  now  in  the  solution  but  it  is  either  oxidized,  or  in  sulphur 
particles.  The  solution  should  be  perfectly  clear,  which  it 
will  be  if  no  metals  were  in  the  assay  which  form  insoluble 
salts  in  sulphuric  acid,  such  as  lead,  barium,  etc.  If  there 
were  such  metals  a  precipitate  will  occur  and  another  course 
must  be  pursued,  which  we  shall  describe.  Put  the  solution 
into  a  dish  and  evaporate  about  one-fifth  with  some  sodium 
chloride,  adding  (toward  the  close  of  evaporation)  some  hy- 
drochloric acid,  cooling  the  dish  each  time  before  adding 
more  acid.  Evaporate  three  or  four  times  to  get  rid  of  nitric 
acid,  adding  the  hydrochloric  acid  each  time.  Determine 
the  sulphuric  acid  as  we  have  shown  by  use  of  barium 
chloride. 


130  MINERALS,    MINES,   AND   MINING. 

Caution. — The  chloride  of  barium  is  soluble  in  some  acids 
and  the  liquor  should,  if  possible,  be  free  from  all  nitric  acid 
or  chlorine  and  have  as  little  free  hydrochloric  acid  as  possible. 
[The  liquor  may  be  tested  for  nitric  acid  and  chlorine,  de- 
tecting the  one-ten-thousandth  part,  by  adding  a  drop  or  two 
of  the  solution  to  20  or  30  drops  of  pure  sulphuric  acid  in  a 
test  tube  and  stirring  the  mixture  with  a  glass  rod  moistened 
at  the  end  with  a  little  brucine.  (Berthemot.)  If  any  nitric 
acid  is  present  the  liquor  becomes  red  and  afterwards  yellow. 
Or,  if  either  nitric  acid  or  chlorine  be  present  in  the  solu- 
tion, a  few  drops  may  be  removed  to  a  test-tube  and  a  little 
solution  of  indigo  in  sulphuric  acid  may  be  added,  enough  to 
give  it  a  blue  color,  and  it  be  heated.  If  any  nitrates  or  chlorine 
be  present  the  color  will  be  changed  to  yellow  in  consequence 
of  the  oxidation  of  the  indigo  at  the  expense  of  the  nitric 
acid  or  the  chlorine.]  The  nitric  acid  may  be  entirely  elimi- 
nated by  repeated  evaporation  with  pure  hydrochloric  acid. 
The  solution  must  be  diluted  considerably  if  the  precipitate 
be  dense  at  first,  and  it  must  be  heated  to  near  boiling  before 
the  barium  chloride  is  added  and  the  solution  allowed  to 
stand  at  a  gentle  heat  for  several  hours.  Care  in  these  last 
movements  will  give  great  accuracy. 

If  any  sulphur  is  floating  in  the  fluid  add  potassium  chlo- 
rate, or  strong  hydrochloric  acid  and  digest  some  time,  plac- 
ing the  dish  upon  a  sand-bath  or  water-bath.  If  all  does 
not  dissolve,  examine,  and  if  the  sulphur  is  all  that  remains, 
and  that  yellow,  filter  off  and  wash  and  weigh  as  sulphur. 
Other  substances  may  be  lead  sulphate,  or  other  sulphates, 
which  must  be  separated  washed  and  examined,  and  the 


COPPER.  131 

other  process  to  which  we  have  referred  in  a  former  para- 
graph be  used  when  lead,  barium,  tin,  calcium,  antimony,  or 
strontium  are  present.  This  process  is  that  of  oxidizing  the 
sulphur  with  chlorine.  The  ore  in  this  case  should  be  pul- 
verized exceedingly  fine,  to  80  to  the  inch  when  largest,  and 
heated  several  hours  with  solution  of  pure  potassa.  Then 
conduct  chlorine  into  the  solution  which  speedily  oxidizes  the 
sulphur  to  sulphuric  acid,  the  potassa  becomes  potassium  sul- 
phate, and  the  oxides  remain  undissol  ved.  Filter  and  wash  the 
precipitates  and  reduce  the  sulphuric  acid  in  the  solution  by 
barium  chloride  as  we  have  described  (noting  the  cautions 
suggested),  but  not  until  after  the  alkaline  solution  is  acidi- 
fied very  slightly  with  hydrochloric  acid.  Arsenic  and  anti- 
mony remain  dissolved  as  acids,  but  the  lead  is  converted 
into  insoluble  binoxide  and  is  filtered  out  as  above  directed. 
If  iron  be  present  there  will  appear  a  red  tint,  and  as  soon  as 
that  is  noticed,  discontinue  the  passing  of  the  chlorine  and 
heat  the  liquid  a  few  minutes  with  powdered  white  quartz 
which  decomposes  the  ferric  acid.  If  the  ore  has  been  ex- 
ceedingly finely  pulverized  much  trouble  will  be  avoided 
from  the  rapid  disengagement  of  oxygen  which  retards  the 
oxidating  by  the  chlorine. 

Where  the  assayer  desires  chiefly  to  know  the  amount  of 
pure  copper  in  the  assay,  or  only  this,  then  he  may  treat  the 
copper  button  extracted  from  the  ore  in  the  crucible  process 
(dry  way),  and  this  he  may  determine  by  the  copper  oxide 
precipitation  method  which  we  have  already  described. 


132  MINERALS,   MINES,   AND   MINING. 


NICKEL. 

Nickel  is  a  white  metal,  hard,  and  susceptible  of  high  polish, 
but  it  is  not  employed  unalloyed.  DUCTILE  and  very  TENA- 
CIOUS. Malleable  when  pure,  but  this  property  is  much  di- 
minished when  carbon  is  present.  It  is  capable  of  welding 
and  is  feebly  magnetic.  Spec.  grav.  8.82  when  hammered. 
Slowly  soluble  in  sulphuric  or  in  hydrochloric  acid,  but 
freely  so  in  nitric  acid  or  nitro-hydrochloric  acid.  It  is  oxi- 
dized if  heated  strongly  in  the  air.  The  ores  are  arsenide 
of  nickel,  niccolite,  hardness  5  to  5.5 ;  grav.  6.7  to  7.3,  me- 
tallic lustre;  pale  copper-red,  with  a  tarnish  and  called,  from 
its  color,  copper-nickel ;  brittle  and  contains  from  about  39 
to  48  per  cent,  nickel,  and  from  about  46  to  54  arsenic,  with 
traces  of  iron,  lead,  cobalt,  antimony,  and  sulphur. 

Before  the  blowpipe,  in  open  tube,  the  traces  of  sulphurous 
acid  may  be  detected,  but  the  arsenous  acid  is  very  plainly 
detected  [by. small  and  white  coating],  the  assay  becoming 
yellowish  green.  On  charcoal  gives  arsenical  fumes  and 
fuses  to  a  globule.  The  last  residue,  if  treated  in  borax 
bead,  gives,  if  slowly  increased  in  heat,  reactions  for  iron, 
cobalt  and  nickel.  (Dana.) 

Nickel  glance  is  an  arseniosulphide  of  nickel  (NiAs2,  NiS2). 
Mineralogical  name  Gersdorffite,  normally  its  composition  is 
arsenic  45.5,  sulphur  19.4,  nickel  35.1  =  100,  but  in  nature 
it  varies  from  33  to  49  per  cent,  arsenic,  22  to  40  per  cent, 
nickel,  and  9  to  21  per  cent,  sulphur,  with  some  iron  and 


NICKEL.  133 

cobalt.  Hardness  5.5  and  grav.  5.6  to  6  or  7.  Form  and 
cleavage :  the  latter  cubic,  the  former  with  variations,  like 
iron  pyrites.  Color :  silver  white  to  steel  gray  and  some- 
times tarnished. 

The  speiss,  so-called,  is  the  residue  from  making  cobalt 
and  contains  iron,  nickel,  and  copper  combined  with  arsenic 
and  sulphur,  which  residue  remains  in  the  bottom  of  the 
crucible.  From  this  residue  much  of  the  nickel  of  commerce 
in  Europe  is  made.  The  Cornish  ores  seldom  yield  more 
than  7  per  cent,  of  nickel. 

There  are  two  oxides  of  nickel  analogous  to  those  of  iron, 
viz:  a  protoxide  and  a  sesquioxide,  the  first  is  precipitated 
from  a  nickel  salt,  by  an  alkali,  as  a  pale  bulky  apple  green 
hydrate,  and  this  is  the  usual  color  of  nickel  salts.  This 
oxide  is  soluble  in  acids  forming  salts  of  nickel.  Ammonia, 
or  ammonic  chloride,  dissolves  this  oxide,  forming  darker 
blue  solutions  (NiO),  atomic  weight  75.  The  anhydrate 
(oxide)  is  best  prepared  by  igniting  the  carbonate  in  a  covered 
crucible ;  it  is  of  a  brownish-green  color. 

The  second,  or  sesquioxide,  may  be  formed  by  heating  the 
carbonate  as  in  the  last  case,  but  gently  and  with  exposure 
to  air ;  in  this  way  a  black  powder  is  obtained.  This  is  in- 
soluble in  acids,  but  on  heating  it  in  nitric  or  sulphuric  acid 
salts  of  protoxide  are  obtained,  Ni2O3,  atomic  weight  166. 

A  chloride  may  be  obtained,  NiCl2,  by  dissolving  the 
protoxide  in  hydrochloric  acid  and  evaporating  the  solution 
to  dryness  and  the  residue  may  be  sublimed  in  yellow  crys- 
tals. 

There  are  three  sulphides,  a  subsulphide,  a  protosulphide, 


134  MINERALS,   MINES,   AND   MINING. 

and  a  disulphide.  The  protosulphide  is  not  precipitated 
from  nickel  solution  by  hydrogen  sulphide  (dihydric),  but 
by  ammonium  sulphide.  It  then  falls  as  a  black  powder  in 
a  hydrated  state.  It  may  be  formed  as  anhydrated  sulphide 
by  heating  nickel  and  sulphur  together,  the  action  is  very 
violent  and  the  combination  takes  place  at  a  lower  point 
than  that  of  the  fusing  point  of  sulphur. 

The  alloys  of  nickel  are  chiefly  those  with  copper  and 
zinc  (German  silver),  and  are  51  copper,  30.5  zinc,  18.5 
nickel.  A  little  cobalt  increases  the  ductility  of  nickel,  but 
arsenic  will  render  it  and  its  alloys  brittle  and  dispose  them 
to  atmospheric  oxidization.  Iron  and  lead  also  tend  to  ren- 
der nickel  and  its  alloys  brittle. 

Nickel  is  always  estimated  as  protoxide,  and  if  it  is  pre- 
cipitated by  potassa  great  care  must  be  taken  in  washing 
out  the  potassa  before  drying  and  weighing. 

The  separation  of  constituents  in  a  nickel  ore  which  con- 
tains arsenic,  copper,  antimony,  lead,  bismuth,  iron,  cobalt, 
barium,  or  calcium  with  the  nickel  is  as  follows:  After  roast- 
ing the  ore,  as  speiss  or  diarsenide  (kupfer-nickel),  powder 
and  dissolve  in  hydrochloric  acid  (concentrated).  Then  add 
to  the  solution  excess  of  hydrosodic  sulphite  (hydrosulphite 
of  soda)  and  boil  till  the  arsenic  acid  is  reduced  to  arsenous 
acid  and  the  excess  of  sulphurous  acid  is  driven  off.  Next 
pass  into  the  warm  solution  hydrogen  sulphide.  Thus  ar- 
senic, copper,  antimony,  lead,  and  bismuth  are  separated 
and  after  standing  some  time  filtered  out.  Evaporate  the 
filtrate  to  dryness  and  the  residue  must  be  dissolved  in 
water.  Chlorine  is  passed  in.  Add  baric  or  calcic  carbon- 


NICKEL.  135 

ate  which  precipitates  iron  and  cobalt.  Sulphuric  acid  is 
now  added  sufficient  to  remove  any  dissolved  barium  or 
calcium.  After  filtering,  sodic  carbonate  is  added  which 
precipitates  nickel  carbonate  and  this  is  reduced  by  heating 
to  redness  after  the  usual  washing  and  drying.  (Cloez.) 

If  the  object  is  to  get  pure  nickel  Deville's  method  is  to 
dissolve  commercial  nickel  in  hydrochloric  acid,  boil  the 
solution  to  dryness,  digest  the  residue  in  water ;  thus  the 
ferric  oxide  is  left.  Dihydric  sulphide  (sulphuretted  hydro- 
gen) is  then  passed  in  to  separate  the  copper  present,  the 
solution  being  diluted  for  the  purpose.  It  is  then  evap- 
orated and  when  sufficiently  concentrated  oxalic  acid  is 
added,  thus  nickel  oxalate  is  precipitated ;  this  is  heated 
intensely  in  a  lime  crucible  (made  by  excavating  a  cavity  in 
a  lump  of  hard  common  lime)  with  a  well  luted  cover,  so 
as  to  exclude  the  air,  thus  the  carbonate  oxide,  formed  by 
the  decomposition  of  the  oxalic  acid,  reduces  the  metal 
itself. 

In  the  United  States  the  ores  of  copper-nickel  found  at 
Gap  Mine,  Lancaster  County,  Penn.,  are  the  chief  and  the 
only  ones,  of  any  consequence,  produced,  but  silicated  ores 
are  found  on  the  Pacific  slope  in  Oregon,  Douglas  County, 
and  the  arsenides  exist  in  Nevada  in  Churchill  County. 
More  recently  (1883)  it  has  been  found  in  the  Sierra 
Nevada  mountain  region  near  Mono  Lake  and  also  in 
Southern  California  from  the  vicinity  of  Corisa  Creek  and 
at  White  River,  Kern  County.  (Williams.) 

The  price  of  nickel  has  so  decreased  in  the  last  ten  years 
(from  $2.60  per  pound  to  $0.75  in  1884)  that  many  of  the 


136  MINERALS,    MINES,   AND   MINING. 

discovered  localities  have  not  been  considered  as  worth  the 
capital  necessary  for  remunerative  working. 

In  examining  for  ores  of  nickel  it  is  almost  invariably 
true  that  some  of  the  masses,  pieces,  or  specimens  will  show 
to  the  naked  eye  or  under  the  magnifying  lens  the  charac- 
teristic apple-green  specks  or  streaks  of  some  of  the  salts  of 
nickel. 

It  is  very  probable  that  vessels  lined  or  plated  with  nickel 
will  be  used  more  extensively  for  culinary  purposes,  since 
the  effects  of  this  metal  upon  the  human  system  appear 
from  experiments  by  F.  Geerkens  less  injurious  than  copper 
or  brass,  and  M.  Mermet  recommends  the  chemist  to  use 
crucibles  of  nickel  in  place  of  silver  as  less  likely  to  melt 
and  far  less  expensive  and  not  more  readily  acted  upon  by 
potash  than  silver. 

The  total  consumption  in  the  United  States  in  1885  was 
about  400,000  pounds  according  to  Williams.  The  coinage 
alone  in  1884  was  399,141  troy  ounces,  which  was  less  than 
in  1883,  when  it  was  703,426  ounces.  A  large  stock  had 
accumulated  which  was  supplied  to  the  market  in  1883  and 
1884,  and  hence  the  total  actual  consumption  cannot  be  told 
by  adding  the  production  of  works  to  the  importations. 

For  the  separation  of  nickel  and  cobalt  see  process  given 
at  close  of  article  on  cobalt. 


IRON.  137 


IRON. 

Iron  does  not  occur  native,  except  as  meteoric. 

When  pure  its  spec.  grav.  is  7.844. 

Its  malleability,  gold  being  1,  is  6,  and  its  ductility  4. 
Its  tenacity  is  1,  lead  being  11,  and  gold  6.  Its  heat  con- 
ducting power  is  6,  silver  being  1,  its  electrical  conducting 
power  being  in  the  same  order. 

Iron  is  universally  present  in  nature,  but  the  true  ores  of 
iron  are  generally  oxides  and  carbonates,  the  sulphides, 
though  found  in  some  places  in  large  amounts,  are  not  used 
as  ores  of  iron,  but  for  the  manufacture  of  sulphuric  acid  and 
for  other  purposes. 

In  Great  Britain  the  chief  ores  are  the  carbonates,  they 
arelfound  in  beds  in  the  coal-formation  and  alternating  with 
layers  of  coal,  and  hence  the  ore  and  fuel  are  found  in  the 
same  place.  Even  the  limestone  used  as  a  flux  in  the  fur- 
nace is  also  associated  with  the  iron  ore,  and  it  is  not  infre- 
quently the  fact  that  the  entire  supply  of  material  used  in 
the  furnace  is  had  on  the  same  tract  with  the  furnace. 

THE  CHIEF  ORES  OF  IRON,  named  in  order  of  their  richness 
in  pure  iron,  are: — 

1.  THE  MAGNETIC  ORES.  The  mineral ogical  name  is  MAG- 
NETITE. Pure  magnetic  ore  is  black  ;  streak  black  ;  brittle  ; 
fracture  conchoidal ;  when  in  crystals  they  are  octahedral,  or 
of  derived  forms,  even  to  dodecahedral,  but  they  are  deter- 
mined by  their  magnetic  quality.  All  these  ores  are  mag- 
netic in  that  they  effect  the  needle  but  have  no  magnetism 


138  MINERALS,   MINES,   AND   MINING. 

necessarily  in  themselves.  When  they  have,  that  is  when 
they  will  attract  a  tack,  or  other  piece  of  iron,  then  they  are 
called  polaric.  Some  fine  and  strong  polaric  ores  are  found 
among  the  Shepard  Mountain  ores  of  Missouri,  but  the  finest 
occur  in  Siberia. 

The  hardness  is  5.5  to  6.5  and  gravity  4.9  to  5.2.  The 
theoretically  pure  specimens  cannot  contain  more  than  72.4 
parts  of  iron,  but  this  degree  of  purity  is  rare  and  never  ex- 
celled in  the  mines.  Yet  we  frequently  hear  peeple  speak 
of  an  ore  of  75  to  SO  or  even  90  per  cent.  iron.  In  the 
Washington  mine,  not  far  from  Marquette,  Lake  Superior, 
the  writer  has  found  semi-crystalline  masses  which  assayed 
nearly  72  per  cent,  and  were  richer  than  any  found  by  him 
in  the  Port  Henry,  Lake  Champlain  region;  the  ore  from 
the  latter  region  carries  with  it  more  silica  in  grains. 

But  these,  while  they  are  the  richest  ores,  are  by  no  means 
the  only  valuable  magnetic  ores.  Rich  magnetic  ores  are 
found  in  some  places  harder  to  work  than  some  of  the  poorer 
magnetic  ores.  The  associations  are  sometimes  quartz,  alu- 
mina, and  sometimes  lime  (azoic  lime),  as  in  the  Champlain 
region,  but  more  injurious  associations  are  found  in  the  sul- 
phur and  copper  united  with  the  ores  as  in  the  Cornwall 
mines  of  Lebanon  Co.,  Penn.  It  is  sometimes  also  associated 
with  small  amounts  of  arsenic  and  phosphorus.  The  sul- 
phur has  the  tendency  to  make  the  iron  break  when  red  hot, 
and  the  phosphorus  when  cold.  The  former  ores  as  well 
as  the  iron  are  called  "  red-short,"  and  the  latter  "  cold-short." 
Small  quantities  of  sulphur  in  an  ore  may,  by  furnace  treat- 
ment, be  rendered  almost  harmless,  and  ores  containing  phos- 


IRON.  139 

phorus  may  be  partially  neutralized  by  the  use  of  ores  con- 
taining sulphur  to  a  certain  amount.  Hence  large  quantities 
of  ores  are  constantly  successfully  used,  which  have  small 
traces  of  either  sulphur  or  phosphorus,  but  care  must  be 
exercised  in  the  introduction  of  an  ore,  as  to  the  amount 
of  either  phosphorus  or  sulphur  contained,  since  even  0.5 
per  cent,  of  the  former  affects  the  tenacity  of  the  iron. 

Very  frequently  loose  fragments  of  magnetic  iron  ore  are 
found  around  upon  the  surface  of  a  country  where  it  cannot 
be  determined  that  any  true  vein  exists,  the  ore  having  been 
transported  by  natural  agencies. 

The  geologic  position  of  magnetite  is  in  the  lowest  rocks, 
granite,  metamorphic,  and  azoic  series.  All  the  remaining 
ores  appear  to  have  been  derived  from  magnetite.  Magnetic 
ore  has  for  its  chemical  composition  iron  and  oxygen,  in 
that  condition  called  a  sesquioxide  and  protoxide,  or  Fe2  O3 
+  FeO  =  Fe3  O4.  By  exposure  to  air  it  changes,  and  the 
iron  takes  all  the  oxygen  for  which  it  has  affinity  and  be- 
comes entirely  Fe2  O3  without  the  protoxide  FeO.  In  that 
mineralogical  form  it  is  called — 

2.  HEMATITE  OR  RED  HEMATITE,  its  streak  being  a  bright 
red;  when  pure  its  hardness  is  5.5  to  6.5,  and  gravity  4.5 — 
5.3.  Sometimes  the  crystals,  or  crystalline  forms  appear 
black  and  extremely  polished,  and  hence  it  is  sometimes 
called  specular  ore,  but  when  very  thin  it  can  be  seen  by 
transmitted  light  as  red  and  translucent. 

This  is  the  larger  source  of  the  iron  of  the  United  States, 
and  its  variations  in  appearance,  hardness,  and  consistency, 
are  numerous.  In  some  specimens  (Jefferson  Co.,  N.  Y., 


140  MINERALS,    MINES,    AND    MINING. 

commercial)  it  presents  the  appearance  of  broken  steel  having 
a  close,  hard,  and  tough  texture,  leaving  fine  micaceous  par- 
ticles. But  the  streak  is  always  red.  At  other  places  it 
appears  in  masses,  somewhat  unctuous  to  the  touch,  and  soft 
as  in  Missouri,  always  red  or  reddish  brown,  containing  as 
high  as  60  per  cent,  or  more  of  iron.  There  is  another 
form  which  the  author  has  traced  from  Central  New  York 
through  Pennsylvania,  and  which  occurs  at  intervals  some- 
what changed  down  to  Georgia,  and  which  contains  small 
grains  of  double  convex  to  perfectly  round  forms  like  large 
shot,  called  fish-egg  ore,  lenticular  ore,  etc.,  but  it  is  a  true 
red  hematite,  and  in  some  sections  it  seems  to  contain  traces 
of  phosphorus. 

Fragments  of  this  ore  frequently  indicate  large  deposits 
not  far  off. 

The  per  cent,  of  iron  in  a  pure  specimen  of  red  hematite 
is  never  over  70  per  cent. 

It  is  asserted  in  some  mineralogical  works  that  this  ore  is 
"  sometimes  attractable  by  the  magnet,  and  occasionally  even 
magnetipolar,"  but  the  writer  has  examined  several  speci- 
mens asserted  to  be  "attractable,"  etc.,  and  in  every  case  the 
specimen  contained  traces  of  magnetite  where  the  red  hema- 
tite had  riot  entirely  been  changed  into  sesquioxide.  Such 
specimens  we  have  found  on  Staten  Island  in  the  hematite 
mine  there  worked.  We  believe  that  the  red  hematite  if 
entirely  homogeneous  is  never  attractable  by  the  magnet. 

3.  BROWN  HEMATITE  is  the  next  ore  in  importance,  and  dif- 
fers from  the  red,  only  that  it  contains,  in  chemical  combina- 
tion, a  portion  of  water  varying  somewhat,  but  generally  about 


IRON.  141 

14  per  cent,  of  its  weight,  when  the  ore  is  fairly  dry.  Streak, 
brown.  Mineralogical  name,  "  Limonite."  Brown  hema- 
tite, when  in  mass  and  pure,  has  a  spec.  grav.  of  3.6  to  4, 
and  hardness  of  5  to  5.5.  Its  composition  in  its  purest  state 
is  as  stated  above,  sesquioxide  of  iron  85.6,  water  14.4,  = 
100.  It,  therefore,  in  its  purest  state  contains  59.89  per 
cent,  of  iron  but  never  more.  The  usual  brown  hematites 
seldom  yield  more  than  30  to  35  per  cent,  iron,  and  are  con- 
sidered very  rich  at  40  to  45  per  cent.  They  are  easily 
worked  and  some  of  the  best  charcoal  irons  are  made  from 
this  ore. 

Its  geologic  position,  as  a  rule,  is  not  in  the  older  rocks, 
but  in  the  secondary,  and  it  seems  to  have  been  derived  from 
the  red  hematite  by  water  agencies.  In  many  parts  of  the 
United  States  the  author  has  found  that  the  largest  and  best 
brown  hematite  beds  are  upon  basins,  at  the  present  time, 
and  that  in  very  many  instances  they  may  be  located  by  ex- 
amining the  country  where  such  ore  does  exist  and  exca- 
vating upon  the  lower  levels,  or  where  ancient  water-sheds 
inclined  away  from  magnetic  ranges. 

The  impurities  of  these  ores  are  generally  alumina,  silica, 
lime,  magnesia,  phosphates,  sulphides,  and  manganese. 

There  are  in  some  mines  (on  the  Lehigh,  opposite  Easton) 
some  peculiarities  of  appearance  in  the  limonite.  Some 
specimens  are  round  and  hollow,  and  when  broken  present  a 
black  concave  surface  of  exceeding  hardness  and  splendid 
polish,  but  the  streak  is  always  brown  and  the  texture 
fibrous  below  the  polished  surface,  and  the  small  amount  of 
silicious  loose  material  found  in  every  polished  geode  seems 


142  MINERALS,   MINES,   AND   MINING. 

to  suggest  the  cause  of  that  polish,  namely,  the  constant 
motion  of  the  geode  through  ages  in  the  moving  waters  of 
some  shallow  lake.  Some  of  these  specimens  show  the 
presence  of  manganese  in  small  quantities,  and  it  is  supposed 
that  the  peculiar  features  of  this  ore  are  due  to  the  presence 
of  that  metal. 

Limonite  (so  called  from  the  Greek  for  a  meadow)  is 
found  as  bog  ore  in  wet  lands  in  nodules,  frequently  in  con- 
centric layers,  and  called  in  some  parts  of  Southeastern  Ohio 
"  kidney  ore."  Sometimes  it  is  found  in  long  sedimentary 
strata  as  in  the  mines  along  the  Lehigh,  Penn.,  and  not  far 
off  in  stalactite  and  rounded  masses  in  the  mines  near 
Allentown.  Also  with  incrustations  of  minute  quartz  crys- 
tals as  at  five  or  six  miles  east  of  Phillipsburg,  N.  J.  The 
mine  at  this  place  is  not  worked,  the  ore  being  too  silicious. 

4.  Another  ore  called  SPATHIC  ORE  is  found  in  smaller 
quantities  in  the  United  States.  It  is  an  iron  carbonate, 
FeCO3.  When  pure  it  contains  48.27  per  cent,  iron,  is  of 
a  light  brown  or  gray  color,  translucent.  Hardness,  3.5  to 
4.5;  grav.,  3.7  to  3.9.  Streak,  white.  Mineralogical 
name,  Siderite.  But  it  has  not  yet  been  found  in  so  large 
quantities  as  to  constitute  an  ore.  In  Connecticut  at  Rox- 
bury  it  occurs  in  veins  in  quartz  in  gneiss. 

In  another  form,  as  argillaceous  carbonate,  of  a  dark  or 
bluish-gray  color  (a  clay  iron-stone),  it  is  found  in  large 
quantities  in  Pennsylvania,  seen  best  in  Johnstown  and 
Northeastern  Ohio ;  considerably  altered  and  associated  with 
coal,  it  formed  some  small  source  of  production  near  Mauch 
Chunk,  Penn.  A  darker  variety  was  mined  in  some  small 


IRON.  143 

quantities  containing  carbonaceous  material  and  called  black 
band  iron  ore,  but  it  was  not  worked  with  much  success  as 
to  quantity.  Some  of  the  latter  kind  of  ore  occurs  in  Ohio 
and  may  yet  be  found  elsewhere.  Black  band  is  used  very 
extensively  in  Scotland. 

These  ores  are  the  chief  sources  of  iron  in  the  United 
States,  and  it  is  to  them  that  the  practical  mineralogist  will 
turn  his  attention. 

It  is  seldom  necessary  to  bring  any  of  these  ores  before 
the  blowpipe,  except  it  be  the  argillaceous,  some  of  which 
so  little  resemble  iron  ore  as  usually  seen  that  there  may  be 
sufficient  reason  for  doubt  as  to  their  composition.  On 
charcoal  any  iron  ore  with  even  a  small  per  cent,  of  iron 
may  with  the  I.  F.  be  reduced  to  metallic  iron  and  by 
means  of  the  magnet  be  shown  to  be  iron.  This  is  espe- 
cially important  where  iron  sulphide  (pyrite)  or  arsenical 
iron  (mispickel)  is  to  be  tested.  The  former  is  frequently 
taken  for  gold  and  the  latter  for  silver ;  the  blowpipe,  I.  F., 
detects  the  mistake  by  reduction  to  metallic  iron  attractable 
by  the  magnet. 

DRY  ASSAY  OF  IRON.  In  order  to  approximate  the  rich- 
ness of  any  ore  of  iron  all  the  ores  may  be  treated  by  the 
following  method  called  dry  assay  : — 

Brasque  a  Hessian  crucible  (as  described  on  page  77)  of 
medium  size  and  introduce  a  weighed  portion  of  a  powdered 
ore.  Cover  it  with  charcoal  to  very  near  the  top,  introduce 
the  crucible  into  a  fire  after  the  crucible  has  been  gradually 
heated  previously  to  thoroughly  drying  it,  and  then  heat  to 
nearly  a  white  heat  for  about  half  an  hour ;  withdraw  the 


144  MINERALS,   MINES,    AND   MINING. 

crucible,  let  it  cool,  and  empty  the  charcoal  upon  a  piece  of 
paper.  At  the  bottom  will  be  found  a  button  of  iron  with 
the  slag  attached  to  one  side,  the  latter  easily  separates  and 
then  the  button  can  be  weighed  and  the  proportion  of  ore 
to  metal  be  approximately  determined. 

Cautions. — It  is  a  mistake  to  pulverize  the  ore  too  finely, 
it  causes  scattering  of  the  reduced  iron ;  the  size  of  the 
powder  should  be  about  that  of  small  pin-heads ;  judgment 
must  be  formed  upon  the  richness  of  the  ore,  lean  ores 
should  be  coarser.  Cover  the  crucible  with  a  piece  of  an 
old  crucible  or  fitted  piece  of  tile  resting  on  the  charcoal. 
Be  sure  that  the  heat  at  the  close  of  the  operation  is  near 
white  heat  for  at  least  ten  minutes  to  melt  the  button  to- 
gether. There  is  no  use  in  breaking  a  brasqued  crucible, 
it  is  safer  to  use  again  a  crucible  which  has  been  used  suc- 
cessfully. In  using  a  tiled  cap  for  your  crucible  or  piece  of 
brick  it  is  always  better  to  rub  wet  charcoal  upon  its  edges 
or  use  plumbago  to  prevent  its  adherence  to  the  crucible. 
In  testing  an  ore  it  is  always  better  to  try  several  assays  and 
note  the  variation  and  take  the  average.  But  the  larger 
the  button  the  more  accurate  the  assay,  because  several  ex- 
traneous additions  to  the  metal  make  the  result  doubtful ; 
first  there  is  a  certain  weight  due  to  carbon  which  must  be 
subtracted  and  this  amount  may  vary  from  about  four  per 
cent,  to  less  than  one ;  some  buttons  may  contain  slightly 
over  four  per  cent.,  but  we  have  frequently,  by  keeping  the 
heat  for  less  than  an  hour  only  to  a  medium  red,  reduced 
the  ore  to  a  nearly  malleable  wrought  iron  with  practically 
little  carbon,  and  it  can  be  heated  so  that  the  iron  shall  con- 


IRON.  1 45 

tain  no  carbon.  In  a  brasqued  crucible  of  the  largest  size 
of  ordinary  nests,  a  button  weighing  two  or  even  three 
ounces  may  be  made,  and  if  broken  through  the  middle  the 
amount  of  carbon  may  be  guessed ;  the  dark,  rough,  semi- 
crystalline,  porous  surface  represents  about  4.25  to  4.50  per 
cent.;  white  or  grayish-white,  smoother,  very  hard,  not 
granular  surface,  may  be  about  2.50  to  3  per  cent.,  and  it  is 
quite  possible  to  produce  a  button  closely  approximating 
steel  of  good  quality,  known  by  its  hardness  and  steely 
grain,  containing  about  1.5,  a  little  more  or  less,  according 
to  treatment.  With  a  little  practice  the  assay er  may  judge 
of  the  heat,  also  the  assay  quantity  of  ore  to  be  used,  the 
time,  and  quality  of  ore  to  make  an  assay  containing  very 
nearly  the  kind  of  carbon  metal  he  wishes.  These  remarks 
take  into  consideration  nearly  pure  ores  and  the  use  of  the 
same  ore  or  similar  ores  at  each  trial. 

Ores  containing  sulphides,  arsenides,  or  selenium  should 
be  roasted  at  a  low  heat,  not  quite  to  red,  after  being  (in 
smaller  assays)  broken  down  to  the  sizes  of  shot. 

Besides  what  we  have  already  said  we  should  state  that 
these  buttons  may  contain  other  impurities  as  phosphorus, 
copper,  titanium,  manganese,  chromium,  and  frequently  mag- 
nesium, calcium,  and  silicon,  and  perhaps  some  other  ele- 
ments which  only  the  wet  assay  may  wholly  eliminate.  But 
notwithstanding  all  these  impurities  the  metal  produced 
always  approximates  the  furnace  product  more  nearly  than 
even  the  wet  and  more  accurate  assay.  And  therefore  it  is 
very  useful. 

In  choosing  samples  for  experiments  from  the  ore  bed  the 
10 


146  MINERALS,    MINES,   AND    MINING. 

assayer  should  use  great  caution,  especially  if  by  this  assay 
he  i>  to  judge  of  a  large  quantity,  or  of  the  entire  mine.  In 
choosing  a  sample  he  should,  if  possible,  visit  the  mine  or 
ore  heap  himself  and  select  from  both  the  smaller  pieces  and 
larger,  have  them  broken  down  together,  mixed  thoroughly 
to  the  amount  of  five  or  ten  pounds,  then  the  pile  quartered 
and  two  diagonally  opposite  quarters  taken  out  mixed  and 
still  further  broken  down  and  divided  in  the  same  way, 
until  the  whole  is  reduced  to  about  three  or  four  ounces, 
which  may  be  passed  through  a  silk  sieve  or  miller's  bolting 
cloth  of  40  to  the  inch.  The  whole  must  be  passed  through 
entirely,  as  silex  and  some  other  impurities,  being  hard, 
remain  until  the  last  sifting,  and  if  they  are  not  passed 
through,  they  materially  change  the  result  in  some  assays. 
In  this  condition  the  ore  may  be  kept  in  a  jar  for  future  use. 
This  size  is  good  for  dry  assay,  as  above  described. 

In  some  cases  where  much  quartz  is  associated  with  the 
ore  it  may  be  well  to  use  about  half  the  assay  weight  of  dry 
lime,  or  fluorspar ;  both  must  be  free  from  any  sulphate  or 
sulphide  (gypsum  or  pyrites).  These  unite  with  the  quartz 
to  form  a  flux  and  then  a  slag.  Where  the  ore  has  little  or 
no  quartz,  sand  or  pounded  glass  may  be  used  to  make  a 
flux  with  the  gangue  of  the  ore,  and  a  little  practice  will 
enable  the  assayer  to  judge  as  to  the  quantity  to  be  used. 
In  this  case  also  a  brasqued  crucible  should  be  used,  or  the 
crucible  be  rubbed  inside  thickly  with  plumbago.  If  the 
reduction  is  performed  in  an  anthracite  coal  furnace,  the  out- 
side of  the  crucible  should  be  rubbed  well  with  plumbago 


IRON.  147 

to  prevent  the  clinging  of  pieces  of  slaty  coal  to  the  cruci- 
bles ;  or  plumbago  (black  lead)  crucibles  may  be  used. 

As  we  have  already  intimated,  the  metal  formed  by  dry 
assay  will  always  weigh  more  than  the  pure  iron,  because  of 
the  impurities  mentioned ;  but,  as  we  have  said,  it  is  very  near 
the  condition  of  the  cast-iron  from  the  same  ore  in  the  blast 
furnace,  and  these  buttons  may  be  subjected  to  the  wet 
method  for  determination  of  other  ingredients  or  elements 
as  found  in  the  button. 

THE  WET  METHOD  enables  the  assayer  to  determine  not  only 
the  iron,  but  every  other  element  in  the  ore.  When,  how- 
ever, the  element  sought  is  only  iron,  the  following  plan 
may  be  pursued: — 

Reduce  the  ore,  as  before  spoken  of,  to  a  finer  powder, 
using  a  bolting  cloth  of  80  to  the  inch,  passing  about  a 
gramme  (15.43  grains)  entirely  through.  Weigh,  and  then 
heat  in  a  porcelain  crucible  to  a  low  red  over  the  blast  alco- 
holic lamp,  or  Bunsen  burner.  When  no  reduction  of 
weight  is  observed,  weigh,  subtract  this  weight  from  the 
first  weight  and  you  have  the  amount  of  water  in  the  ore, 
both  mechanically  combined  and  the  chemically  combined 
water.  Transfer  the  assay  to  your  beaker  glass — the  size  of 
the  beaker  glass  should  be  about  7  by  3  inches,  or  larger — 
pour  upon  the  assay  about  an  ounce  of  muriatic  acid  (hydro- 
chloric acid,  HC1)  and  digest  with  low  heat  till  the  ore  dis- 
appears in  the  solution,  stir  with  a  glass  rod,  or  narrow  slip 
of  glass,  or  platinum  wire,  and  add  a  little  nitric  acid  (25  or 
30  drops),  and  after  solution  is  fully  effected,  add  about  four 
or  five  ounces  water,  stir,  now  add  slowly  aqua  ammonia 


148  MINERALS,   MINES,   AND   MINING. 

till  a  precipitate  begins,  stir  again  and  add  more  ammonia 
till  apparently  no  additional  precipitate  appears.  If  the 
solution  smells  of  ammonia,  stop,  stir  with  the  glass  rod  and 
let  it  settle.  This  precipitate  now  contains  all  the  iron  in 
the  condition  of  sesquioxide.  In  a  few  minutes  it  will  settle 
towards  the  bottom  of  the  beaker.  But  the  precipitate  con- 
tains also  all  the  alumina  of  the  ore,  if  there  was  any,  but  it 
is  quite  soluble  in  caustic  potass.  Add  now  a  piece  of  a 
stick  of  caustic  potass  about  one  inch  and  a  half  in  length 
while  the  solution  is  quite  warm ;  if  any  hissing  or  commo- 
tion takes  place,  as  is  usual,  wait  till  all  is  dissolved  and  heat 
and  stir  for  about  ten  minutes  till  the  solution  is  a  little  below 
boiling  point,  stop  and  let  the  temperature  remain  the  same. 
You  have  now  probably  dissolved  all  the  alumina,  and  the 
sesquioxide,  undissolved,  is  precipitated  in  the  solution.  Let 
all  stand  till  nearly  cool,  giving  ample  time  for  any  floating 
sesquioxide  to  settle.  Some  specks  will  hold  up  because  of 
a  minute  bubble  of  air,  but  cooling  will  collapse  them  and 
they  may  all  sink.  If  not,  touch  them  with  the  rod.  Now 
if  only  iron  is  to  be  ascertained,  prepare  your  filter  paper 
upon  the  glass  funnel  over  another  beaker,  stir  the  solution 
and  slowly  pour  it  out  upon  the  filter  paper  until  the  whole 
has  passed  through.  Add  some  more  warm  water  from  your 
washing  ("  spitz")  bottle,  till  all  of  the  assay  is  out  of  the 
beaker  and  upon  the  filter.  Now  comes  the  washing  of 
the  soft  sesquioxide.  Use  the  spitz  to  stir  up  the  precipitate 
by  blowing  the  stream  on  the  filter  paper  around  the  mass, 
then  into  it,  let  it  settle,  dose  it  again,  and  after  you  have 
passed  about  a  pint  of  hot  water  upon  it,  lift  the  funnel  off 


IRON.  149 

the  beaker  and  let  six  or  eight  drops  of  the  solution  fall 
into  a  small  test  tube,  replace  the  funnel  over  the  beaker 
and  let  fall  one  drop,  or  less,  of  silver  nitrate  into  the  test 
tube.  If  there  yet  remains  a  trace  of  hydrochloric  acid,  a 
milky  appearance  (silver  chloride)  is  seen.  Continue  the 
washing  for  a  time,  which  must  be  according  to  the  density  of 
the  milky  precipitate,  or  until,  on  again  testing,  no  milkiness 
appears.  Put  the  funnel  with  filter  aside  covered  from  dust, 
and  let  it  dry.  It  will  shrink  to  less  than  one-quarter  its 
size.  When  dry  it  is  easily  detached  from  the  filter  paper, 
and  may  then  be  transferred  to  the  porcelain  cup,  or  platinum 
crucible  for  heating  till  all  water  is  driven  off;  this  requires 
a  low  red  heat  continued  till  no  decrease  of  weight  is  per- 
ceptible. If  great  accuracy  is  required,  and  every  particle 
and  even  iron  stain  cannot  be  removed  from  the  filter  paper, 
then  the  filter  paper  must  be  burned,  as  we  have  already 
described,  but  more  particularly  again.  After  the  mass  and 
all  particles  have  been  removed  from  the  assay  paper,  the 
paper  itself  must  be  rolled  up,  or  torn  in  pieces  carefully  so 
as  to  lose  nothing,  and  burned  to  ashes  in  the  crucible  either 
with  the  oxidizing  flame  of  the  blowpipe,  or  better  over  the 
alcoholic  blast  lamp,  till  every  particle  becomes  a  white  ash 
and  no  carbon  specks  remain.  Cool  it  and  weigh.  Subtract 
the  former  noted  weight  of  that  paper's  ash  from  the  latter 
weight  of  the  burned  filter  ash  and  sesquioxide,  and  you 
have  the  amount  of  only  that  sesquioxide  which  adhered  to 
the  filter  paper.  This  weight  must  be  added  to  the  weight 
of  the  mass,  and  you  have  then  almost  accurately  the  whole 
amount  of  sesquioxide,  every  100  parts  of  which  contain  70 


150  MINERALS,   MINES,   AND   MINING. 

parts  of  pure  iron,  if  it  is  in  a  state  of  purity.  We  say 
"  almost  accurately,"  for  the  sesquioxide  very  probably,  de- 
spite the  washing,  holds  very  little  of  the  potash.  But  where 
extreme  accuracy  is  not  necessary  the  potash  may  be  very 
nearly  washed  out  by  using  boiling  hot  water,  long  con- 
tinued, until  no  residue  appears  upon  a  bright  strip  of  pla- 
tinum, or  silver,  after  evaporating  upon  it,  in  a  flame,  a  drop 
of  the  filtrate. 

The  precipitate  (sesquioxide)  may  be  separated  from  the 
potash  much  more  readily,  after  a  little  washing  with  nearly 
boiling  water,  by  re-dissolving  upon  the  filter,  by  hydrochloric 
acid  dropped  upon  it,  and  after  all  has  passed  through,  pre- 
cipitating by  ammonia  again,  the  solution  being  made  hot, 
and  washing.  Time  is  saved  by  this  process.  Care  must  be 
taken  to  wash  all  the  dissolved  sesquioxide  through  the  filter 
before  precipitating  with  ammonia.  The  sesquioxide  is  now 
ready  (see  below)  for  extracting  phosphorus. 

If,  however,  you  wish  corroborative  proof  and  accuracy, 
with  less  washing,  Wohler's  method  is  the  best,  namely : 
Neutralize  the  dilute  solution  of  the  ore  (before  precipitation 
by  ammonia)  with  carbonate  of  sodium,  add  to  it  hyposul- 
phite of  sodium,  and  boil  until  sulphurous  acid  ceases  to  be 
evolved,  that  is,  until  it  cannot  be  detected  by  the  smell. 
The  alumina  collects  as  a  pretty  dense  precipitate,  which 
only  needs  to  be  filtered,  washed,  calcined  by  red  heat  and 
weighed.  If  properly  performed,  the  alumina  must  be 
white,  entirely.  To  the  solution,  after  a  little  concentration 
by  evaporation,  add  potassium  chlorate  (a  gramme  or  more), 
and  hydrochloric  acid,  filter  to  separate  some  particles  of  free 


IRON.  151 

sulphur,  and  then  precipitate  the  iron  sesquioxide  by  am- 
monia, just  as  before.  The  weight  of  the  alumina  may  now 
be  ascertained. 

FOR  PHOSPHORUS.  The  iron  sesquioxide  may  contain  this 
element,  and  as  its  amount  is  a  fact  to  be  studied  in  iron 
metallurgy,  we  must  examine  the  sesquioxide  carefully, 
thus  :  The  sesquioxide  remaining  upon  the  filter,  as  spoken 
of  in  the  second  paragraph  above,  or  any  peroxide  precipi- 
tated by  ammonia  from  a  hot  solution,  contains  the  phos- 
phorus. The  following  method  is  the  best  for  its  determina- 
tion :  dissolve  the  finely  pulverized  ore  in  hydrochloric  acid, 
adding  15  or  20  drops  of  nitric  acid  to  reduce  all  protoxide 
to  sesquioxide  (peroxide),  then  heat  the  solution,  using  as 
little  acid  as  possible  beyond  the  quantity  necessary  for  dis- 
solving the  ore. 

Note :  If  all  the  ore  is  not  dissolved  at  first,  then  con- 
tinue heating  and  agitating  with  a  glass  rod ;  if  not  yet 
soluble,  then  either  separate  the  insoluble  particles  by  filtra- 
tion, triturate,  heat  with  caustic  soda  and  dissolve  again, 
or  begin  with  a  new  supply  of  ore  (a  gramme),  and  after 
putting  the  very  finely  triturated  ore  into  a  platinum  cru- 
cible, add  4  to  5  grammes  of  caustic  soda,  or  potash,  or 
the  sodic-potassium  (see  page  58),  heat  slowly  to  red  heat, 
moderating  the  heat  till  all  effervescence  ceases,  then  increas- 
ing the  heat  and  continuing  till  all  is  dissolved  and  is  tran- 
quil, remove  the  crucible,  cool  it  on  a  cold  plate  rapidly,  and 
place  it  in  a  porcelain  dish  containing  water  sufficient  to  cover 
it.  Add  a  few  drops  of  hydrochloric  acid  and  heat  the  dish, 
and  continue  adding  hydrochloric  acid  till  all  is  dissolved. 


152  MINERALS,   MINES,    AND   MINING. 

After  this,  wash  out  the  platinum  crucible,  that  is,  rinse  out 
all  its  contents  in  order  that  nothing  be  lost  and  evaporate 
the  liquid  to  dryness.  This  last  process  renders  all  the  solu- 
ble silica  insoluble  even  in  the  hydrochloric  acid  with  its 
little  water  which  may  be  added  and  the  whole  now  thrown 
upon  a  filter  paper,  filtered  and  washed ;  the  silica  remains 
in  the  filter  and  the  iron  with  its  phosphorus  passes  through 
into  the  filtrate.  Wash  the  white  silica  well  so  that  no 
cloudiness  appears  in  the  filtrate  when  tested  with  silver  ni- 
trate, as  we  have  before  described,  and  this  filter  paper  may 
be  removed  to  dry,  and  its  silica  weighed  when  ready,  and 
the  filter  burned  as  we  have  shown  where  great  accuracy  is 
required. 

Remove  the  alumina,  as  before  directed,  precipitating  the 
peroxide  which  is  now  clear  of  silica  and  alumina  and  you 
are  ready  to  remove  the  phosphorus.  With  proper  care,  as 
we  shall  direct,  the  molybdate  of  ammonium  is  the  reagent 
to  be  used.  An  aqueous  solution  of  this  reagent  is  to  be 
preferred  to  that  in  nitric  acid  (see  under  Reagents),  com- 
monly employed.  Its  strength  is  but  from  50  to  60  grammes 
to  the  litre  (1.7  pint)  of  water.  Phosphorus  is  not  precipi- 
tated by  this  reagent  from  neutral  solutions,  and  on  the 
other  hand  strongly  acid  solutions  retard,  or  even  resist  pre- 
cipitation. 

Parry's  method,  the  accuracy  and  value  of  which  Mallet 
has  proved,  is  as  follows :  Add  ammonia  to  the  solution  un- 
til a  complete  precipitation  occurs  of  peroxide  of  iron.  Add 
cautiously  as  much  nitric  acid  as  is  just  sufficient  to  redis- 
solve  the  precipitated  peroxide.  Bring  the  solution  to  boil 


IRON.  153 

and  add  the  molybdate  of  ammonia  in  the  proportion  of 
about  30  cubic  centimetres  to  the  quarter  litre  of  iron  solu- 
tion (i.  e.,  about  14  fluidounces  to  8J  ounces)  or  a  little 
more  if  it  be  rich  in  phosphorus.  The  usual  yellow  precipi- 
tate may  appear  immediately,  but  if  not,  boil  briskly  again 
for  a  few  minutes,  add  a  very  few  drops  of  nitric  acid,  and 
shake  the  closed  flask  vigorously  at  intervals,  and  continue 
to  add  a  drop  or  two  more  of  nitric  acid  until  a  distinct  pre- 
cipitate is  observed  to  commence.  The  ebullition  must  now 
be  stopped  or  a  bulky  flocculent  precipitate  will  rapidly 
form ;  but  the  flask  should  be  kept  hot  and  as  near  to  the 
boiling-point  as  possible  (without  actual  boiling),  and  shake 
briskly  now  and  then.  In  from  an  hour  or  two  to  four  or 
five  hours  the  whole  of  the  phosphorus  will  usually  have 
precipitated  in  a  good  granular  form.  If  these  details  be 
fully  observed,  it  is  seldom  necessary  to  repeat  the  process  in 
order  to  obtain  the  whole  of  the  phosphorus  present.  The 
yellow  precipitate  separated  by  filtration,  washed  with  water 
and  molybdic  solution  (equal  volumes),  is  redissolved  after- 
wards on  the  filter  with  the  aid  of  ammonia.  Pour  into 
this  ammoniacal  solution  a  solution  of  sulphate  of  magne- 
sium, which  precipitates  the  phosphoric  acid  in  the  ordinary 
form  of  double  phosphate  of  ammonium  and  magnesium. 
The  precipitate  is  thrown  on  a  filter,  washed  with  cold  water 
containing  a  third  of  its  volume  of  ammonia,  then  dried, 
calcined,  and  weighed,  as  Mg2P2O7  or  2MgOP2O5.  In  cal- 
cining (with  red  heat)  it  loses  ammonia  and  water.  In  this 
precipitate  phosphorus  is  27.92  per  cent,  of  the  whole  and 
the  P2O5  (phosphoric  acid)  63.96  per  cent.  (See  p.  41.) 


154  MINERALS,   MINES,   AND   MINING. 

Care  must  be  taken  not  to  calcine  the  phosphate  too 
rapidly,  else  it  will  not  have  time  to  oxidize  the  carbon 
particles  which  may  have  fallen  into  it  from  the  filter  paper 
or  from  some  other  source,  and  the  mass  may  be  dark.  To 
avoid  this,  raise  the  temperature  slowly  to  redness ;  in  this 
way  the  precipitate  becomes  pulverulent,  and  the  organic 
matters  are  completely  burned  away. 

In  these  processes  we  have  separated  from  the  iron  and 
determined  the  elements  alumina,  silica,  and  phosphorus. 
The  peroxide  of  iron  may  be  precipitated  as  before,  or  it 
may  now  be  determined  from  a  fresh  amount  of  ore  of  same 
weight  dissolved  in  hydrochloric  acid,  the  peroxide  of  iron 
and  the  alumina  precipitated  by  ammonia  in  excess,  heated, 
and  the  precipitate  washed,  dried,  and  calcined.  The  weight 
of  the  alumina,  silica,  and  phosphoric  acid  subtracted  from 
the  precipitated  sesquioxide  leaves  the  weight  of  the  pure 
sesquioxide.  The  pure  iron  may  now  be  deduced  thus: 
Fe2O3  (sesquioxide  anhydrous)  112  +  48  =  160,  that  is,  every 
160  parts  contain  112  of  iron,  or  70  per  cent.  The  various 
weights  of  assays  must  in  their  sum  equal  the  original  weight 
of  the  assay,  or  we  must  look  for  other  elements. 

In  the  filtrate  from  the  iron  and  alumina  may  remain  lime 
and  magnesia.  The  lime  may  be  precipitated  by  oxalate  of 
ammonium  added  in  excess,  after  warming  the  solution,  and 
allowing  it  to  stand  for  ten  or  twelve  hours.  If  any  adhere 
to  the  glass,  drop  a  few  drops  of  nitric  acid  upon  it  and  pre- 
cipitate it  again  with  the  ammonium  oxalate  and  add  it  to 
the  other.  Instead  of  filtering,  as  it  is  difficult,  the  super- 
natant liquid  may  be  decanted  until  near  the  precipitate  and 


IRON.  155 

the  latter  then  thrown  upon  a  filter  previously  wetted  with 
a  little  water  and  alcohol  to  facilitate  filtration  without  loss, 
and  washed  with  warm  water.  Dry  and  calcine  slowly  to  a 
red  heat  and  keep  it  at  this  heat  until  changed  from  oxalate 
of  lime  to  carbonate  and  then  to  caustic  lime  from  which  all 
the  carbonic  acid  (CO2,  carbonic  dioxide)  has  been  driven 
off.  It  can  then  be  weighed  as  lime  (CaO).  It  is  well  to 
try  this  lime  in  the  porcelain  or  platinum  crucible  by  drop- 
ping a  little  hydrochloric  acid  upon  it  after  adding  a  drop  or 
two  of  water. 

If  there  is  no  CO2,  there  will  be  no  effervescence ;  if  there 
is,  then  the  reduction  of  the  ammonium  oxalate  to  lime  was 
not  well  done.  You  must  now  add  a  few  drops  of  sulphuric 
acid,  evaporate  with  care  to  dryness,  calcine  at  a  low  heat, 
and  after  cooling  weigh  and  from  the  sulphate  of  lime  thus 
formed  (CaOSO4)  the  lime  may  be  determined,  being  41.17 
per  cent.  The  magnesia  still  remains  in  the  solution  and 
this  may  be  determined  by  adding  ammonia  in  excess,  then 
a  solution  of  phosphate  of  sodium  also  in  excess,  set  aside 
for  12  to  24  hours.  After  this  filter,  washing  with  cold 
water  containing  one-quarter  to  one-third  of  ammonia,  dry, 
calcine  to  low  red  heat,  cool,  and  weigh,  36.03  per  cent,  of 
which  is  MgO  =  magnesia. 

Cautions. — To  the  inexperienced  it  may  be  necessary  to  use 
test  papers  to  determine  the  alkaline,  or  acid,  condition  of 
assays.  The  preparation  of  these  we  have  described  in  the  be- 
ginning of  this  part  of  the  work  (p.  63).  But  a  little  practice 
will  decide ;  ammonia  in  excess  may  be  known  by  the  smell, 
even  when  the  excess  is  small.  Always  stir  a  solution  im- 


156  MINERALS,   MINES,    AND   MINING. 

mediately  before  testing.  So  with  sulphuretted  hydrogen 
and  ammoniacal  sulphides  when  used  and  eliminated  by  boil- 
ing, their  presence  or  absence  may  be  tested  by  the  smell. 
In  stirring  solutions  learn  to  stir  without  much  striking  the 
sides;  some  testing,  as  for  magnesia,  requires  care  not  to 
scratch  or  even  touch  the  glass,  but  where  the  amount  of 
magnesia  is  small  the  precipitation  may  be  promoted  by 
drawing  the  glass  rod  over  the  inside  of  the  glass,  in  contact 
but  not  by  scratching. 

In  precipitating  lime,  when  it  bears  a  small  proportion  to 
that  of  the  magnesia  present,  the  assay  for  lime  must  be 
particularly  careful,  for  it  goes  down  in  part,  and,  if  very  small, 
wholly  with  the  magnesia.  So  if  this  condition  is  suspected 
both  the  lime  and  magnesia  must  be  converted  into  sulphates, 
as  we  have  explained  when  the  assayer  has  failed  to  reduce 
the  oxalate  to  lime,  but  has  injured  his  assay  by  not  suffi- 
ciently calcining.  In  the  assay  the  lime  sulphate  is  not 
soluble  in  alcohol,  while  the  magnesia  sulphate  is,  and  so  the 
two  may  be  separated  and  the  magnesia  be  afterward  pre- 
cipitated. 

FOR  SULPHUR.  The  ore  may  yet  contain  S  from  some  sul- 
phide of  iron,  of  barium  of  lime  or  of  copper,  but  generally 
as  sulphide  of  iron.  As  sulphur  is  important  in  its  influence 
upon  the  wrought  iron  produced,  it  is  important  to  be  exact 
in  the  analyses  for  this  element,  and  it  had  better  be  deter- 
mined from  a  freshly  made  solution  of  ore. 

The  most  satisfactory  way  to  ascertain  the  sulphur  in  the 
ore,  whether  brown  or  red  hematite  or  magnetite,  is  finely  to 
pulverize  the  ore,  sift  (80  to  the  inch),  dry  and  mixed  with 


IRON.  157 

four  or  five  times  its  weight  of  caustic  potass,  or  soda,  or  a 
mixture  of  both  (see  Reagents),  place  in  the  platinum  cruci- 
ble, begin  heating  slowly  and  increase  the  heat  to  red  as  the 
effervescence  ceases,  until  a  tranquil  fusion  is  effected. 
Time  will  depend  upon  the  nature  of  the  ore  and  the  fine- 
ness to  which  it  was  reduced.  During  the  fusion  carefully 
add  about  twice  its  weight  (of  the  ore)  of  nitrate  of  potas- 
sium (dry  and  in  small  pieces).  The  better  way  is  to  mix 
carbonate  of  soda  10  parts  and  carbonate  of  potassium  14 
parts,  and  of  this  mixture  take  4  times  the  weight  of  the 
ore  to  be  assayed ;  add  twice  the  weight  of  the  ore,  of 
nitrate  of  potassium  all  dry,  and  when  the  ore  is  being 
heated  in  the  platinum  crucible,  add,  by  degrees,  the  powder 
until  all  has  been  added  and  all  is  in  tranquil  fusion.  Let 
it  cool,  and  treat  with  hydrochloric  acid  till  all  is  completely 
dissolved,  evaporate  to  dryness  for  silicic  acid  (as  we  have 
already  described)  and  to  decompose  the  nitrate.  The 
residuum  is  now  to  be  moistened  with  hydrochloric  acid, 
and  afterward  treated  with  hot  water,  filtered,  and  thus  the 
silicic  acid  separated,  the  solution  should  be  perfectly  clear. 
We  are  now  ready  to  precipitate  the  sulphur  as  sulphate 
of  barium,  but  it  must  be  done  carefully  by  adding  in  small 
quantities  of  chloride  of  barium.  If  the  ore  contained  iron 
pyrites,  it  is  always  better  to  add  a  weaker  solution  of  the 
barium  chloride  in  order  not  to  make  too  dense  a  precipi- 
tate. 

If  the  ore  contains  calcium  sulphate  or  iron  sulphate 
(gypsum  or  native  copperas,  so  called)  it  must  first  be  boiled 
in  water,  filtered,  and  what  is  soluble  be  treated  until  all  the 


158  MINERALS,   MINES,   AND   MINING. 

sulphur  is  determined  by  the  chloride  of  barium,  and  after- 
ward treat  the  insoluble  residue  as  described  above. 

Caution. — The  barytic  sulphate  thus  produced  may  retain 
some  of  the  alkaline  salts  used,  and  this  has  sometimes  made 
an  error  in  excess  in  the  assayer's  analysis  for  sulphur. 
Stolba  (so  Mallet)  says  it  is  better  after  the  filtrate  comes 
away,  apparently  free  from  barytic  sulphate,  to  place  all  the 
latter  in  another  beaker  and  release  it  by  rewashing  after 
treating  it  in  a  small  beaker  with  a  solution  of  neutral  ace- 
tate of  copper  with  some  acetic  acid  added,  and  then  digest- 
ing it  at  a  boiling  heat.  After  about  five  minutes'  heating 
throw  it  again  upon  the  filter  and  filter  and  wash  anew. 
Thus  the  sulphur  may  be  very  closely  found  after  careful 
drying  and  calcining  the  sulphate  at  low  red.  The  per 
cent,  of  sulphur  in  barium  sulphate  is  13.73. 

The  above  elements,  silica,  alumina,  lime,  magnesia,  phos- 
phorus, and  sulphur  are  all  which  occur  as  the  general  ac- 
companiments in  the  brown  hematite  ores,  very  rarely 
barium,  but  in  some  ores  manganese  forms  a  very  important 
part,  and  it  is  well  to  become  acquainted  with  the  process  of 
determining  this  element. 

MANGANESE.  After  the  reactions  with  the  blowpipe,  one 
of  which  we  have  sufficiently  pointed  out  in  the  beginning  of 
this  part  (p.  31),  and  a  better  one  under  MANGANESE,  indicate 
the  presence  of  this  element,  we  proceed  to  determine  its 
quantity  as  follows : — 

The  shortest  way  is  to  use  carbonate  of  barium.  The 
solution  of  the  ore  is  saturated  with  carbonate  of  sodium, 
testing  the  solution  with  litmus  paper  until  very  little  free 


IRON.  159 

acid  shows  itself.  Then  add  an  excess  of  carbonate  of 
barium,  stir  well  and  let  it  act  cold  for  about  half  an  hour, 
stirring  the  liquid  frequently.  Separate  the  precipitate  by 
filtration.  This  contains  the  peroxide  of  iron,  phosphoric 
acid,  and  alumina,  combined  with  some  of  the  carbonate  of 
barium.  Wash  with  cold  water,  and  the  filtered  liquid  con- 
tains the  manganese,  lime,  magnesia,  and  a  salt  of  barium. 
The  precipitate  may  be  proceeded  with  as  we  have  before 
directed  to  obtain  iron,  alumina,  and  phosphoric  acid,  the 
only  additional  care  being  to  get  rid  of  the  barium.  This 
must  be  done  by  redissolving  the  precipitate  over  a  new 
beaker  separately  with  hydrochloric  acid,  washing  all 
through,  and  precipitating  the  barium  with  dilute  sulphuric 
acid  and  separating  by  filtration.  You  are  now  ready  to 
precipitate  as  before  with  ammonia,  collect  the  filtrate,  and 
proceed  as  we  have  shown.  Use  Wohler's  process  as  always 
preferable  to  the  usually  adopted  method  of  using  caustic 
potash  to  separate  the  alumina,  unless  it  is  not  necessary  to 
be  extremely  accurate.  We  have  described  this  already. 
If  you  have  room  enough  in  the  same  beaker,  a  new  one 
need  not  be  used,  but  the  precipitate  dissolved  with  hydro- 
chloric acid  a  little  diluted  and  run  off,  using  the  same 
filter  and  beaker,  washed  with  warm  water  slightly  acidu- 
lated with  hydrochloric  acid  and  the  filtrate,  thus  diluted, 
boiled  and  then  the  barium  precipitated  by  sulphuric  acid 
diluted.  Let  the  solution  stand  until  all  is  settled,  separate 
the  barium  sulphate  by  filtration,  and  then,  as  we  have  al- 
ready shown,  precipitate  the  peroxide,  alumina,  and  the 


160  MINERALS,   MINES,    AND   MINING. 

accompanying  phosphoric  acid  by  ammonia,  filter,  wash,  and 
proceed  for  alumina  and  phosphoric  acid  as  we  have  directed. 
The  clear,  colorless  liquid  which  contains  the  manga- 
nese, lime,  and  magnesia  must  be  poured  into  a  matrass 
and  heated  slightly.  The  liquid  now  contains  chloride  of 
ammonium  from  the  use  of  both  hydrochloric  acid  and  the 
ammonia  to  precipitate  the  peroxides;  this  condition  is  neces- 
sary in  order  to  proceed  for  the  manganese.  Add  hydrosul- 
phide  of  ammonium  to  precipitate  the  manganese.  If  the 
iron  has  been  previously  carefully  and  entirely  precipitated, 
the  precipitate  will  be  of  a  very  clear  rose  color ;  any  gray- 
ish or  black  color  will  show  that  some  lack  of  care  has 
pre-existed  and  iron  remains.  After  twelve  hours'  rest,  the 
matrass  being  either  corked  or  covered  with  a  watch  crystal, 
the  hydrated  sulphuret  of  manganese  will  be  entirely  pre- 
cipitated. After  some  time  the  color  may  change  to  a 
greenish  tint,  due  to  the  fact  that  the  hydrated  sulphuret  of 
manganese  loses  a  little  water  of  hydration,  but  this  is  imma- 
terial. The  precipitate  may  now  be  filtered  with  some  care, 
thus :  Filter  off  the  liquid  from  the  precipitate  and  add  the 
latter  to  a  solution  of  chloride  of  ammonium  in  another 
vessel,  to  which  some  drops  of  the  hydrosulphide  have  been 
added,  let  it  settle,  and  then  decant  the  whole  upon  the 
same  filter  and  add  this  solution  to  that  first  made.  If 
there  are  any  signs  of  remaining  sulphuret  of  Mn  in  the 
solution,  run  it  through  again.  Now  wash  the  precipitate 
with  distilled  water  containing  a  little  both  of  the  hydrosul- 
phide and  of  the  chloride  of  ammonium,  and  as  the  washing 
proceeds  diminish  the  quantity  of  chloride  of  ammonium 


IRON.  161 

and  toward  the  close  omit  it  entirely.  The  danger  exists  in 
the  change  of  sulphuret  of  manganese  into  protosulphate ; 
the  latter  being  soluble  may  pass  over  into  the  filtrate. 
Hence  the  use  of  the  hydrosulphide  to  prevent  this  change, 
but  care  should  be  taken  to  keep  the  filter  full  and  thus 
protect  the  precipitate  from  contact  with  the  air  as  much  as 
possible. 

The  first  of  the  filtrate  may  be  somewhat  turbid ;  if  so, 
filter  for  awhile  and  throw  back  this  turbid  filtrate  when 
the  liquor  flows  clear.  The  precipitate  may  now  either  be 
washed,  dried,  and  calcined,  protected  from  the  atmosphere 
as  much  as  possible  and  weighed,  or  more  accurately  thus : 
treat  the  precipitate  and  filter  with  hydrochloric  acid  some- 
what diluted,  avoiding  excess  beyond  that  necessary  fully  to 
dissolve  the  precipitate..  The  sulphuret  of  manganese  is 
now  changed  into  the  soluble  chloride  and  hydrosulphuric 
acid  gas  is  given  off.  Heat  the  solution  till  the  passage  of 
hydrosulphuric  acid  gas  ceases  and  filter  to  get  rid  of  all 
particles  which  may  be  floating  in  the  liquor.  Boil  the 
solution  and  add  very  cautiously,  a  little  at  a  time,  carbonate 
of  sodium  (lest  too  much  effervescence  causes  loss),  until  the 
solution  shows  slight  alkaline  rea'ction  (using  reddened  lit- 
mus paper  for  this  purpose).  The  precipitate  now  is  proto- 
carbonate  of  manganese.  Wash  several  times  by  decanta- 
tion,  filling  the  jar  or  beaker  with  hot  water,  letting  the 
precipitate  settle,  and  pouring  off.  Then  throw  it  upon  a 
filter,  passing  all  through,  and  continue  the  washing  till  a 
polished  platinum  strip  shows  no  residue.  Dry  and  calcine 

strongly,  as  in  reducing  carbonate  of  lime  to  lime,  in  contact 
11 


162  MINERALS,   MINES,   AND   MINING. 

with  the  air  and  weigh ;  every  hundred  parts  contain  72.05 
parts  manganese,  that  is,  of  the  resulting  Mn3O4,  72.05  per 
cent,  is  manganese. 

The  solution  may  now  be  heated  to  boiling  and  the  hy- 
drosulphide  of  ammonium  completely  decomposed  by  adding 
hydrochloric  acid  slowly  until  no  sulphuretted  hydrogen 
remains;  this  can  be  known  by  the  absence  of  all  smell. 
Filter  to  separate  the  deposited  sulphur,  neutralize  with 
ammonia,  and  proceed  to  separate  lime  and  magnesia  as 
already  directed. 

SPATHIC  ORE,  or  ore  containing  carbonic  dioxide,  CO2,  as 
iron  carbonate.  The  determination  of  CO2  is  the  same  as 
in  marble  or  any  lime  carbonate  and  is  made  by  using  a 
small  glass  instrument,  formerly  called  Kipp's  apparatus,  of 
the  following  form  (Fig.  5).  Into  B  put  the  carbonate, 
powdered,  dried,  and  weighed,  through  the 
hole  at  D  ;  add  a  little  water.  Into  A  hydro- 
chloric acid  is  poured  through  C,  after  fixing  the 
glass  stopper  tube  in  its  place,  till  A  is  nearly  full. 
Wipe  dry  and  weigh  the  whole.  Draw  the 
tube  D  out  through  the  cork  so  far  that  the 
lower  end  will  not  come  in  contact  with  the 
carbonate  when  the  latter  effervesces;  now  draw 
the  tube  C  up  a  little  so  as  to  drop  a  few  drops  of  the  acid 
upon  the  carbonate  and  let  the  effervescence  subside ;  then 
drop  some  drops  again  and  repeat  this  process  until  all  effer- 
vescence entirely  ceases  to  come  off.  Draw  out  the  cork  at 
D  and  with  a  perfectly  dry  glass  tube  blow  gently  into  B 
through  the  open  hole  until  all  CO2  has  been  driven  out, 


IRON.  163 

and  if  the  vessel  is  warm  from  the  action  of  the  acid  upon 
the  carbonate,  let  it  stand  till  as  cool  as  when  the  acid  was 
poured  in.  Now  weigh  the  whole  again.  It  will  weigh 
less  than  before ;  subtract  the  latter  from  the  former  weight 
and  the  weight  of  the  GO2  will  be  had  as  that  of  the  car- 
bonic dioxide  (CO2)  of  the  iron  carbonate  weighed  at  first, 
and  this  will  be  nearly  accurate ;  the  only  inaccuracy  will 
result  from  carelessness  and  the  loss  of  moisture  escaping 
through  the  tube  at  D.  The  latter  may  be  provided  against 
by  having  a  short  glass  tube  with  a  cork  tightly  fixed  in 
one  end  with  a  hole  sufficiently  large  to  admit  the  end 
of  the  small  tube  at  D.  When  all  things  are  ready  and 
just  before  weighing  fill  this  larger  tube  with  some  small 
pieces,  the  size  of  about  one-eighth  or  one-fourth  inch  diam- 
eter, of  calcium  chloride.  The  escaping  gas  will  leave  its 
moisture  in  the  salt  and  the  dry  gas  only  will  escape ;  the 
upper  end  of  the  short  tube  may  have  a  piece  of  cork  cut 
to  fit  in  loosely  so  as  to  allow  the  gas  to  escape  and  yet  not 
allow  much  contact  with  the  outside  air. 

In  the  use  of  this  carbonic  dioxide  apparatus,  some 
experience,  care,  and  skill  are  required,  and  the  student 
should,  for  his  own  practice,  try  this  CO2  determination  at 
least  three  or  four  times,  before  feeling  that  he  is  competent 
to  use  the  apparatus. 

Several  other  shapes  and  sizes  of  carbonic  dioxide  appara- 
tuses are  offered,  but,  as  skill  in  the  operator  is  the  chief 
matter,  there  is  none  superior  to  the  last  mentioned,  in  the 
hands  of  the  careful  manipulator ;  in  fact  with  two  of  the 
smallest  beaker  glasses,  usually  found  in  a  "  nest,"  a  prac- 


164  MINERALS,   MINES,   AND   MINING. 

tised  analyst  may  make  a  very  good  analysis  of  CO2  by 
placing  the  weighed  carbonate  with  water  in  one  beaker,  the 
acid  in  the  other  and  weighing  the  two  glasses,  treating 
them  as  above  suggested,  weighing  again  and  subtracting 
the  latter  from  the  former  weight.  But  this  last  process  is 
not  so  convenient  as  with  the  single  instrument. 

The  Kipps,  and  any  other  apparatus  of  this  kind,  may  be 
had  at  any  chemist's  wareroom. 

TITANIC  ACID.  Immense  quantities  of  a  dark-colored  iron 
sand  are  found  in  Nova  Scotia,  and,  a  few  years  ago,  on  Hon- 
duras Bay,  and  more  recently  in  various  parts  of  the  United 
States  and  Territories.  This  sand  contains  iron  and  titanic 
acid.  It  has  also  occurred  in  some  magnetite  ore  in  New 
Jersey  in  very  small  per  cent.,  and  yet  so  as  to  show  itself 
in  the  furnace  slags  on  the  Lehigh,  and  wherever  titaniferous 
iron  ores  are  smelted,  but  the  furnace  products  do  not  appear 
to  be  TiO2,  but  TiCy23Ti3N2.  As  a  mineral  it  is  called  rutile, 
which  contains  sometimes  over  98  per  cent,  of  titanic  acid 
(TiO2).  The  iron  sand  sometimes  possesses  as  much  as  40 
per  cent.  Some  ores  contain  less  than  3  per  cent,  and  can 
then  be  used  in  the  furnace,  but  any  per  cent,  over  that 
amount  causes  the  ores  to  be  rejected,  although  in  wrought 
iron  made  from  such  ores  the  effect  is  to  strengthen  the  iron, 
and  in  certain  proportions  its  action  is  to  make  a  steely  iron. 
The  difficulty  as  to  the  use  of  these  ores  in  the  furnaces  is 
that  the  associated  lime  and  coal  (flux  and  fuel),  called 
"  charges,"  must  be  somewhat  modified  to  keep  up  the  same 
grade  of  pig  iron. 

Under  the  blowpipe,  titanic  acid,  even  though  combined 


IRON.  165 

with  iron,  may  be  detected  by  treating  a  small  particle  first 
in  a  bead  of  phosphate  of  soda  in  which  no  color  appears 
except  from  the  iron  in  the  R.  F.,  but  after  treating  the  bead 
with  metallic  tin  upon  charcoal  a  violet  color  appears  more 
or  less  apparent  according  to  the  amount  of  titanium.  TiO2 
is  not  soluble  in  acids,  but  may  be  made  soluble  by  heating 
to  fusion  with  caustic  alkalies,  or  their  carbonates.  An  ex- 
cess of  acid  is  then  added,  and  with  the  addition  of  tin  foil 
it  gives  a  decided  violet  color,  especially  when  concentrated. 
To  extract  TiO2  from  the  iron  sand,  or  titanic  iron  ore,  the 
substance  is  finely  pulverized  and  fused  with  three  parts  of 
carbonate  of  potash  [or  soda  potash] ;  on  washing  the  mass 
with  hot  water  a  part  of  the  alkali  is  removed  and  an  acid 
titanate  of  potash  left  mixed  with  the  iron  oxide.  This  is 
dissolved  in  hydrochloric  acid  and  the  solution  evaporated 
to  dryness,  when  the  titanic  acid  and  any  silicic  acid  which 
may  be  present  are  converted  into  the  insoluble  modifica- 
tions and  are  left.  The  residue  is  again  digested  with 
hydrochloric  acid,  is  washed  with  water  (by  decantation,  for 
titanic  acid  easily  passes  through  the  filter),  dried  and  fused 
at  gentle  heat  with  bisulphate  of  potash.  The  sulphuric 
acid  forms  a  soluble  compound  with  the  TiO2  which  may  be 
extracted  by  cold  water,  leaving  the  silicic  acid  undissolved. 
The  solution  containing  the  titanic  acid  is  mixed  with  about 
twenty  times  its  volume  of  water,  and  boiled  for  some  time, 
when  the  titanic  acid  is  separated  as  a  white  precipitate, 
exhibiting  a  great  inclination  to  cling  as  a  film  to  the  surface 
of  the  flask  in  which  the  solution  is  boiled,  and  giving  it  the 
appearance  of  being  corroded.  TiO2  becomes  yellow  when 


166  MINERALS,   MINES,   AND   MINING. 

strongly  heated,  and  white  again  on  cooling;  it  does  not 
dissolve  in  solution  of  potash  like  silica,  but  forms  a  titanate, 
which  is  decomposed  by  water ;  the  acid  titanate  of  potash 
which  is  left  may  be  dissolved  in  hydrochloric  acid,  and  if 
the  solution  be  neutralized  with  carbonate  of  ammonia, 
hydrated  titanic  acid  is  precipitated,  very  much  resembling 
alumina  in  appearance.  (Bloxam.) 

VOLUMETRIC  DETERMINATION. 

We  shall  preface  the  explanation  of  this  method  by  saying 
that  while  it  is  a  very  convenient  one  under  exceeding  care, 
it  is  nevertheless  attended  with  the  difficulty  that  inexpe- 
rienced analysts  may  need  considerable  practice  before  accu- 
racy can  be  claimed  in  the  results  arrived  at.  It  would  be 
well  for  a  beginner  to  assay  a  piece  of  pure  iron  wire  by 
the  process  already  described  by  ammonia  precipitation,  etc., 
and  then  experiment  with  the  volumetric  determination, 
comparing  results. 

VOLUMETRIC  DETERMINATION  by  potassium  permanganate 
depends  upon  this  fact,  that  a  definite  amount  of  this  salt  in 
solution  will  change  a  definite  amount  of  a  solution  of  a 
ferrous  salt  (FeO)  into  a  ferric  salt  Fe2O3.  If  we  know  how 
much  iron  in  the  ferrous  state  (FeO)  can  be  changed  into 
the  ferric  state  (Fe2O3)  by  100  cubic  inches  of  a  certain 
strength  of  solution  of  permanganate  of  potassium,  we  can 
readily  know  the  amount  of  iron  in  any  solution  of  an  ore, 
without  either  weighing  or  separating  any  of  the  associated 
elements,  by  simply  measuring  the  proportion  of  solution  of 
permanganate  taken  up  in  the  change. 


IRON.  167 

THE  PREPARATION.  Dissolve  5  grammes  of  pure  crystal- 
lized potassium  permanganate  in  a  litre  of  water  and  preserve 
it  in  a  well-stopped  bottle  away  from  the  light.  It  does  not 
readily  alter,  but  should  occasionally  be  tested  as  to  its 
efficacy. 

PREPARATION  OF  THE  TEST  IRON.  Weigh  off  carefully  one 
gramme  of  thin  (yL  inch)  clean  piano  wire,  transfer  it  to  a 
J  litre  (nearly  half  pint)  flask  having  a  mark  or  measure  line 
of  capacity,  containing  100  cub.  cent,  (about  3  oz.)  of  dilute 
sulphuric  acid,  1  part  to  8  of  water.  Add  a  little  sodium 
bicarbonate  simply  to  evolve  a  little  CO2  to  keep  air  out, 
and  then  stop  the  flask  with  an  india-rubber  cork  provided 
with  a  tube  for  evolution  into  another  flask  containing  20  or 
30  c.  c.  (about  one  ounce)  of  water.  Previously  to  proceed- 
ing any  further,  boil  about  300  c.  c.  (8  or  9  oz.)  of  water  to 
exclude  all  the  air  and  place  it  aside  to  cool.  Heat  now 
the  first  flask  containing  the  iron  carefully  to  boiling  till  the 
iron  is  dissolved,  and  the  evolved  hydrogen  wdll  escape  into 
the  water  of  the  second  flask,  the  tube  being  bent  so  as  to 
pass  at  right  angles  down  into  and  under  the  water  surface 
in  the  second  flask. 

It  should  be  stated  that  the  tube  passing  out  of  the  flask 
containing  the  iron  should  be  bent  at  right  angles  and  be 
similar  to  another  right-angle  piece  leading  into  the  second 
flask.  The  benefit  of  two  tubes  is  that  a  piece  of  india- 
rubber  tubing  of  a  couple  of  inches  in  length  may  be  slipped 
over  each  tube  end  and  thus  allow  of  a  clip,  or  pinch  stop, 
between  the  two  flasks  to  cut  off  the  communication  between 
them,  when  such  action  is  needed.  Thus,  when  the  iron  is 


168  MINERALS,    MINES,    AND    MINING. 

boiled  to  entire  dissolution  in  the  dilute  sulphuric  acid,  the 
clips  can  first  be  put  on,  and  after  removing  the  lamp  the 
flasks  will  no  longer  be  in  communication.  After  the  solu- 
tion cools,  open  the  clip  and  the  partial  vacuum  in  the  first 
flask  will  now  draw  the  water  up  from  the  second  flask,  and,  by 
so  adding  the  water  which  was  boiled  and  put  aside  to  cool, 
the  first  flask  may  be  filled  to  the  mark  which  as  we  said  at 
first  indicated  J  litre  (7  oz.).  This  solution  contains  now 
one  gramme  of  iron  wire,  which  we  will  suppose  contains 
.996  pure  iron,  because  by  general  assays  piano  wire  is  sup- 
posed to  contain  .4  carbon.  This  wire  must  be  assayed  if 
great  precision  and  certainty  are  required.  But  we  now 
proceed  to  draw  out  of  the  flask,  by  means  of  a  pipette,  50  c.  c. 
of  the  iron  solution  containing  -J-  of  the  iron  (the  \  litre  = 
250  c.  c.),  and  transfer  to  a  beaker  of  400  c.  c.  capacity,  then 
dilute,  until  the  beaker  is  half  full  and  place  it  upon  a  sheet 
of  white  paper  that  the  changes  of  color  may  be  seen.  Fill 
a  burette,  graduated  accurately,  with  the  permanganate 
solution.  Now  add  the  permanganate  to  the  ferrous  solution, 
stirring  it  well  all  the  time.  At  first  the  red  drops  disappear 
rapidly  and  then  more  slowly,  the  solution  gradually  chang- 
ing to  a  yellowish  tint ;  then  proceed  slowly  until  the  last 
drop  imparts  a  faint,  though  unmistakably  reddish  tint, 
which  remains  even  on  stirring.  Stop  and  let  the  perman- 
ganate solution  be  carefully  read  off  and  the  cubic  centi- 
metres noted  with  great  exactitude.  The  amount  of  per- 
manganate solution  should  be  about  20  c.  c.  Repeat  the 
experiment  with  another  50  c.  c.  of  the  iron  solution,  and 
compare  the  two  notings:  there  should  be  not  over  .1  of  a 


IRON.  169 

c.  c.  of  difference.  If  there  is  a  greater  difference,  try 
again  another  50  c.  c.  Practice  will  perfect  the  beginner. 
From  the  average  calculate  from  the  quantity  of  permanga- 
nate used  the  amount  of  iron  changed  by  100  c.  c.  First 
divide  the  iron  weighed  off  at  the  beginning  by  5  and  multi- 
ply by  .996  (the  per  cent,  of  pure  iron  in  the  wire  used) ;  this 
gives  the  amount  of  iron  in  50  c.  c.  of  the  solution.  Thus, 
suppose  we  took  1.050  gramme  of  iron  wire  and  used  a  mean 
of  21.3  c.  c.  of  permanganate,  then  1.050  divided  by  5  is  .210, 
multiplied  by  .996  equals  .20916,  which  is  the  amount  of  iron 
in  21.3  c.  c.  Then  21.3  :  .20916  : :  100  :  .98197,  that  is,  for 
every  100  c.  c.  of  that  solution  of  permanganate  used  .98197 
is  the  proportion  of  pure  iron  represented.  This  is,  in  the 
main,  the  method  as  described  in  Fresenius,  and  it  is  added 
that,  if  there  is  a  deficiency  of  free  acid  in  the  solution  of 
iron,  the  fluid  acquires  a  brown  color,  turns  turbid,  and  de- 
posits a  brown  precipitate  (manganese  dioxide  and  ferric 
hydroxide).  The  same  may  happen  also  if  the  solution  of 
permanganate  is  added  too  quickly,  or  if  the  proper  stirring 
of  the  iron  solution  is  omitted  or  interrupted.  In  these  cases 
the  result  is  not  satisfactory.  That  the  fluid  reddened  by 
the  last  drop  of  solution  of  potassium  permanganate  added 
loses  its  color  again  after  a  time  need  create  no  surprise  or 
uneasiness;  this  decolorization  is,  in  fact,  quite  inevitable,  as 
a  dilute  solution  of  free  permanganic  acid  cannot  keep  long 
undecomposed.  (Fresenius.) 

It  is  plain  that  when  the  per  cent,  of  iron  is  all  that  is 
needed,  all  that  is  required  is  to  pulverize  the  iron  ore,  weigh 
and  dissolve  in  hydrochloric  acid  and  reduce  the  iron  to  the 


170  MINERALS,    MINES,   AND   MINING. 

protoxide  condition  (ferrous)  and  then  note  the  proportion  of 
potassium  permanganate  solution  required  exactly  to  change 
the  ferrous  to  the  ferric  state  in  the  assay  and  state  the  pro- 
portion, thus:  the  weight  of  the  assay  ore  we  will  suppose  is 
2  grammes  and  of  the  solution  of  permanganate  used  is  50 
c.  c.,  which  was  proved  to  be  equivalent  to  (half  of  100,  which 
was  shown  to  be  .9819)  .490+  of  iron.  Then  the  amount  of 
iron  present  is  .490  of  a  gramme  in  2  grammes  of  the  ore. 

To  prepare  the  ore  for  the  assay  we  must  see  to  it  that 
the  condition  of  all  the  iron  therein  is  that  of  ferrous  salt. 
In  order  to  this  condition  the  ore  should  be  dissolved  as  usual 
in  hydrochloric  acid,  using  a  little  more  than  is  absolutely 
necessary  to  dissolve  it.  Let  it  be  entirely  free  from  nitric 
acid.  The  condition  now  is  that  of  a  ferric  solution,  and 
by  dropping  in  small  pieces  of  granulated  zinc,  which  has 
been  found  free  from  iron,  hydrogen  begins  to  form  imme- 
diately and  passes  out  of  the  flask,  which,  if  it  has  a  long 
narrow  neck,  will  drive  out  the  atmosphere  and  the  solution 
will  become  paler  as  the  ferric  chloride  changes  to  the  ferrous 
chloride.  If  sulphuric  acid  was  used  instead  of  hydrochloric 
acid,  the  state  of  the  iron  would  be  that  of  ferric  sulphate  and 
ferrous  sulphate.  Use  a  moderate  heat  and  more  zinc  until 
the  color  having  been  perfectly  removed,  that  is,  the  ferric 
having  been  changed  into  a  ferrous  condition,  you  are  now 
,  ready  to  add  the  potassium  permanganate  from  the  gradu- 
ated burette,  as  we  have  already  described.  If  the  zinc  con- 
tains iron,  as  is  frequently  the  case,  and  perfectly  free  zinc 
cannot  be  obtained,  the  zinc  must  be  analyzed  for  iron,  and 
the  proportion  of  iron  in  the  weight  used  must  be  subtracted 


IRON.  171 

from  the  amount  of  iron  found  in  the  solution,  and  this  zinc 
be  always  that  which  shall  be  used  with  its  stated  amount 
of  iron. 

If  the  presence  of  the  atmosphere  is  objectionable  because 
that  the  analysis  is  desired  to  be  extremely  accurate,  then 
the  passage  of  CO2  into  the  flask  over  the  solution  from  a 
prepared  bottle  kept  for  this  purpose,  may  be  provided  for, 
and  the  surface  of  the  ferrous  solution  kept  from  the  oxidiz- 
ing influence  of  the  atmosphere  until  the  volumetric  deter- 
mination has  been  made. 

A  ferric  solution  may  be  changed  into  a  ferrous  by  passing 
hydrogen  sulphide  through  the  solution  while  cold.  Con- 
tinue passing  the  hydrogen  sulphide  some  minutes  after  the 
color  due  to  the  ferric  condition  has  been  changed  entirely. 
Then  cautiously  increase  the  heat  to  boiling  and  continue 
boiling  till  all  the  hydrogen  sulphide  passes  off  and  produces 
no  discoloration  upon  lead  paper  held  at  the  mouth  of  the 
flask.  When  the  boiling  is  discontinued  fill  the  flask  to 
within  an  inch  of  its  mouth  and  close  with  a  stopper  and 
cool  rapidly  in  a  basin  or  stream  of  cold  water.  It  is  now 
ready  for  volumetric  determination. 

The  hydrochloric  acid  should  be  removed  from  the  solution 
before  the  change  of  ferric  to  ferrous  state  is  produced,  and 
this  may  be  done  by  adding  sulphuric  acid  in  excess  and 
evaporating  the  solution  as  long  as  hydrochloric  acid  vapors 
pass  off  at  a  temperature  of  about  212°  F.  (100°  C.).  Add 
water  on  cooling  and  digest  till  any  ferric  sulphate  crystals 
which  may  have  formed  are  dissolved.  Care  must  be  taken 
to  add  sulphuric  acid  liberally.  If  there  should  prove  to  be 


172  MINERALS,   MINES,    AND   MINING. 

much  barium,  calcium,  or  any  salt  which  when  combined 
with  sulphuric  acid  might  form  an  insoluble  salt,  the  process 
by  using  zinc  would  be  preferable,  as  these  insoluble  salts 
may  hold  some  iron.  If,  therefore,  after  evaporating  with 
sulphuric  acid,  and  subsequent  treatment  with  water,  any 
insoluble  residue  remains,  it  must  be  examined  for  iron. 

The  above  method  is  generally  preferred  to  others  which 
may  be  found  in  some  works  on  analysis,  and  where  care 
has  been  taken  to  keep  the  potassium  permanganate  solution 
always  regulated,  and  skill  used  in  reading  off  the  amount 
used,  a  few  experiments  will  make  the  performer  quite  ready 
and  the  process  become  very  easy  and  accurate.  This 
method  of  determination  of  iron  becomes  very  important  in 
the  hands  of  a  skilful  manipulator,  as  enabling  the  analyst 
to  determine  "  by  difference"  the  amount  of  other  ingredients 
in  an  ore ;  thus,  if  he  has  the  weight  of  a  precipitate  contain- 
ing peroxide  of  iron  and  alumina,  having  by  volumetric  deter- 
mination the  weight  of  the  iron,  he  may  know  that  of  the 
alumina  by  simply  subtracting  the  weight  of  the  iron  from 
the  whole.  Or,  if  he  has  the  alumina  by  actual  analysis  in 
a  peroxide  which  he  suspects  contains  phosphoric  acid,  he 
may  proceed  in  the  same  way — adding  the  alumina  to  the 
determined  iron  and  subtracting  the  weight  of  the  two  from 
the  whole ;  if  anything  be  over,  it  will  be  that  of  the  phos- 
phoric acid,  if  the  assay  contains  nothing  else.  Such  a 
method  of  determination  by  subtraction  is  termed  analysis 
"  by  difference,'*  and  in  some  cases  is  of  great  importance. 


IRON.  173 

EXHAUSTION  OF  IKON  ORE  DEPOSITS. 

Before  we  close  this  section  relating  to  iron  we  add  the 
following  remarks  recently  (1887)  furnished  for  publication 
by  Major  John  W.  Powell,  Director  of  the  Geological  Sur- 
vey : — 

"  The  great  increase  in  the  production  of  pig  iron,  from 
4,529,869  short  tons  in  1885  to  5,600,000  short  tons  during 
the  year  1886,  has  led  to  much  inquiry  as  to  the  source  of 
the  ores  which  made  this  increase  possible ;  for  it  is  a  well- 
known  fact  that  even  the  ordinary  production  is  a  drain  upon 
the  ore  deposits  sufficient  to  exhaust  the  present  sources  of 
actual  supply  in  a  short  period — perhaps  in  thirty  years — 
more  probably  in  much  less  time.  The  Government  has 
given  sufficient  attention  to  the  general  geology  of  the  coun- 
try, however,  to  afford  a  good  grasp  on  the  distribution  of 
the  iron  ores,  and  the  geologists  have  also  defined  the  charac- 
ter of  the  ores  so  well  as  to  direct  the  explorers  accurately  to 
the  profitable  fields.  The  statement  was  made  last  year  by 
me  that  within  thirty  years  the  necessary  exploration  for 
new  iron  ore  mines  would  exceed  that  of  Great  Britain, 
where  every  available  deposit  is  being  traced  to  the  furthest 
extent.  The  years  1885  and  1886  have  shown  the  justice 
of  this  prediction  in  the  development  of  new  fields  to  support 
the  increased  production. 

"  The  new  Gogebic  district  in  the  vicinity  of  Gogebic  lake, 
Ontonagon  Co.,  Michigan,  which  produced  1022  tons  in 
1884,  increased  to  111,661  tons  in  1885,  and  increased  this 
fourfold  in  1886,  has  been  the  scene  of  unparalleled  devel- 


174  MINERALS,    MINES,   AND    MINING. 

opments,  and  the  same  is  true  of  the  Vermillion  district  of 
Minnesota.  The  confidence  with  which  capital  has  been 
invested  in  these  new  claims  is  due  to  the  advice  of  the  geolo- 
gists to  extend  the  mines  in  this  direction.  That  the  new 
mines  are  the  result  and  not  the  cause  of  the  increased  pro- 
duction of  iron  and  steel,  is  shown  by  the  increased  imports 
of  Spanish  ores  during  the  last  year,  as  the  result  of  higher 
prices.  This  shows  that  the  remedy  for  prospective  ex- 
haustion is  still  further  exploration  for  the  mines  to  which 
the  geologist  points  in  various  parts  of  the  country.  Many 
of  the  large  deposits  have  been  neglected,  as  not  suitable  for 
making  steel  by  the  ordinary  acid  process,  and  in  others  the 
percentage  of  iron  is  not  attractive.  But  much  attention 
will  undoubtedly  be  given  to  these  ores  within  the  next  few 
years.  This  tendency  is  seen  at  one  locality  in  Tennessee 
by  the  increase  from  70,757  long  tons  in  1884  to  94,319 
long  tons  in  1885,  and  even  the  siliceous  ores  at  Cornwall, 
Pa.,  show  increased  use." 


TIN. 

Pure  tin  has  a  spec.  grav.  of  7.292,  and  belongs  to  the 
white  metals,  as  silver,  platinum,  aluminium,  etc.,  but  the 
spec.  grav.  will  readily  distinguish  the  metal  as  tin.  In  a 
bar  it  is  easily  detected  by  the  crackling  sound  emitted  when 
bent  back  and  forward.  Excepting  lead  and  zinc,  it  is  the 
least  tenacious,  and  hence  lead  is  the  only  common  metal 
which  is  more  difficult  to  draw  into  wire  at  ordinary  tempe- 


TIN.  175 

rature.  Tin  may  be  drawn  at  212°  F.  (Bloxam.)  Melts 
at  442°  F.  and  not  easily  vaporized.  Only  gold,  silver,  and 
copper  are  more  malleable.  Its  chemical  symbol  is  Sn,  and 
its  combining  number  or  "atomic  weight"  is  118,  or,  exactly, 
117.6980. 

OCCURRENT  FORM.  It  rarely  occurs  native,  and  then  it  is 
combined  with  lead  and  even  gold  in  Siberia.  (Dana.) 
Also  as  an  oxide  of  tin  (binoxide)  (tin  78.67,  oxygen  21.33 
if  pure),  massive  and  in  crystals  of  a  lustrous  black,  or  brown, 
and  grav.  from  6.4  to  7.1,  and  hardness  6  to  7,  sometimes 
nearly  transparent  to  entirely  opaque.  Called  then  tin- 
stone, either  as  crystal,  or  massive.  The  streak  is  white  or 
grayish  and  brownish.  It  is  brittle.  The  crystals  take  a 
four-sided  shape  (tetragonal,  right  prismatic)  with  tetragonal 
termination  and  variations  from  this  form,  the  edges  being 
sometimes  replaced  by  planes,  so  that  some  appear  almost 
eight-sided.  Mineralogical  name  is  Cassiterite.  It  also 
occurs  as  a  sulphuret,  containing  copper,  iron,  and  zinc,  of  a 
theoretic  ratio  corresponding  to  sulphur  29.5,  tin  27.2, 
copper  29.3,  iron  6.5,  zinc  7.5  =  100;  this  is  in  foreign  speci- 
mens. H.  4.  Grav.  4.3  =  4.5,  with  metallic  lustre,  and,  when 
pure,  of  a  steel  gray,  but  varying  to  a  bronze-like  appear- 
ance and  then  called  bell-metal  ore.  Mineralogical  name, 
Stannite. 

The  nodular  or  rounded  grains  of  tin  found  in  beds  of 
streams  and  in  alluvial  soil,  and  called  stream-tin,  are  very 
pure  tin-stone  (binoxide);  as  found  in  the  alluvial  soil  of  the 
island  of  Banca  it  is  considered  the  best  in  the  world.  Only 
a  small  portion  of  this  island  has  been  explored  for  tin  and 


176  MINERALS,   MINES,   AND   MINING. 

that  in  the  north  part,  but  the  yield  is  about  4000  tons 
annually.  In  Cornwall  the  tin  mines  have  been  worked 
from  remote  antiquity,  but  the  tin  is  mixed  with  various 
sulphurets  and  minerals,  as  copper,  blende  (zinc),  arsenic, 
fluor,  apatite  and  tungstate  of  iron  and  manganese  (wol- 
fram). The  latter  requires  special  treatment. 

LOCALITIES  AND  GEOLOGY.  It  occurs  in  various  other 
countries  besides  the  ones  stated  above,  as  Austria,  Siberia, 
Saxony,  in  Australia,  arid  in  form  of  cassiterite  in  some  places 
in  the  United  States:  Maine,  Massachusetts,  New  Hamp- 
shire, New  York,  Virginia,  North  Carolina,  Georgia,  Cali- 
fornia, Idaho,  and,  as  asserted,  in  Missouri,  but  not  in 
quantities  sufficient  to  invite  much  outlay  for  working. 
From  a  mistaken  notion  as  to  the  appearance  of  tin  ore, 
several  announcements  have  been  made  of  discoveries  in 
various  places  where  no  tin  was,  and  in  others  where  the 
amount  of  tin  was  so  small  and  the  associations  so  difficult 
to  separate  and  in  such  preponderance,  that  the  discoveries 
were  without  commercial  value.  And  yet  there  are  indica- 
tions of  its  workable  existence  in  Missouri  and  California. 

At  present  the  appearance  of  large  quantities  of  tin -ore  in 
Dakota  with  various  associations,  and  in  some  parts  almost 
pure,  seems  to  indicate  that  it  has  a  wide  and  valuable  dis- 
tribution. The  district  in  Dakota,  where  the  chief  deposit 
has  been  found  (June,  1883),  is  at  the  central  portion  of  the 
Black  Hills,  in  Pennington  County,  about  twenty  miles  south- 
west of  Rapid  City,  two  miles  from  Harney  City.  It  is  at 
the  claim  known  as  the  Etta,  on  an  isolated  conical  granitic 


TIN.  177 

hill  rising  about  250  feet  above  the  surrounding  valley,  4500 
feet  above  the  sea. 

The  geological  surroundings  of  the  Black  Hills  are  those 
of  the  outcropping  edges  of  the  sedimentary  formations  from 
the  base  of  the  Silurian  upward  to  the  Tertiary,  so  far  as  they 
exist  in  the  far  West.  These  formations  dip  gently  away  on 
all  sides  from  the  central  nucleus  of  the  more  ancient  rocks 
which  rise  up  in  a  multitude  of  irregular  peaks  and  broken 
ridges  with  a  general  northerly  and  southerly  trend.  These 
rocks  consist  chiefly  of  fine-grained  mica  schist  and  micace- 
ous sandstones,  traversed  by  veins  of  quartz,  which  are  often 
auriferous.  In  some  portions  the  slates  may  be  said  to  be 
garnet-slates,  as  they  contain  20  per  cent,  of  garnet,  rather 
than  mica  slates.  The  mineral  called  staurolite,  from  the 
cross-like  appearance  of  some  of  the  crystals,  is  also  very 
frequent  in  the  rocks;  staurolite  is  a  silicate  of  iron  and 
alumina  with  some  magnesia.  The  transition  from  these 
schists  to  the  granite  is  sudden. 

The  tin  ore  seems  to  be  in  granulated  or  disseminated  con- 
dition in  a  rock  composed  of  small  scales  of  mica  and  albite 
feldspar,  called  "  greisen,"  hand  samples  of  which  contain 
from  6  to  10  per  cent,  of  concentrated  ore.  It  is  thought 
probable  that  it  will  be  profitable  to  work,  even  if  some  of 
it  does  not  carry  more  than  10  pounds  of  tin  ore  to  the  ton. 
The  general  average  of  the  ores  raised  from  the  mines  at 
Cornwall,  England,  appears  to  be  less  than  3  per  cent.,  being 
under  60  pounds  of  "  block  tin"  (concentrated  tin  ore)  to  the 
short  ton  of  ore.  Some  of  the  greisen  from  Dakota,  sent  to 

the  New  York  metallurgical  works,  assayed  4.6  per  cent,  of 
12 


178  MINERALS,   MINES,    AND   MINING. 

block  tin,  equivalent  to  2.95  of  pure  tin.  Some  of  the 
massive  "kidney"  ore  from  the  Etta  mine  yielded  44.1  per 
cent.,  according  to  the  reports  of  the  company. 

Tinstone  has  also  been  discovered  in  the  northwest  parts 
of  the  Black  Hills,  in  Wyoming,  and  stream  tin  in  beautiful 
brown  grains  on  Jordan  creek,  Idaho,  with  gold  in  the  placer 
deposits  of  that  stream.  Also  in  1876  a  bar  of  tin  was 
shown  at  the  Centennial  Exposition,  made  from  wood-tin, 
in  small  rounded  light  brown  colored  grains  about  the  size 
of  peas,  or  kernels  of  corn,  from  Montana,  not  far  from  Helena. 
The  composition  of  one  of  these  ores  shows  the  associations 
of  the  tin  oxide  as  follows :  The  analysis  is  by  Dr.  F.  A. 
Genth,  of  an  ore  from  California,  the  Temescal  tin  mines  at 
Cajalca : — 

Silicic  acid          .         .         .         .         .        ••••'.  9.82 

Tungstic  acid      .      .  .         .       ,  -.'•     ;.      ;.*.•,-*;  .22 

Oxide  of  tin        .         .         .         .     ..  •,        *         .  76.15 

Oxide  of  copper          •       {•         .         «         .         .  .27 

Oxides  of  iron  and  manganese,  lime  and  alumina  13.54 


100.00 

MINERALOGICAL  APPEARANCE.  As  the  chief  ore  is  that  of 
the  dioxide,  sometimes  called  binoxide  (Sn  O2)  or  cassiterite, 
attention  should  be  paid  to  its  appearance  in  the  mass,  or  in 
grains.  As  the  spec.  grav.  of  the  usual  ore  is  not  quite  that 
of  the  pure  tinstone,  it  is  difficult  to  detect  it  by  the  weight, 
although  as  we  have  stated  the  pure  is  nearly  if  not  quite  7, 
or  very  little  lighter  than  cast  iron.  It  is,  therefore,  much 
heavier  than  quartz,  which  is  2.5  to  2.8  and  in  hardness  in 
some  cases  quite  equal  to  quartz.  In  color,  however,  its 


TIN.  179 

variations  may  perplex,  as  it  is  found  black,  brown,  brownish- 
red  and  in  the  wood-tin  mixed  shades,  generally  with  con- 
centric shades  and  botryoidal  shapes.  Sometimes  it  has  a 
reddish  hue,  gray  yellow,  or  even  white.  The  streak  is  not 
always  white,  but  grayish  and  even  brownish. 

It  has  been  confounded  with  tourmaline  by  those  not 
well  informed,  also  with  brown  garnet.  From  the  former  it 
may  readily  be  distinguished  by  the  lightness  of  tourmaline  3, 
tinstone  7,  and  the  streak  of  tourmaline  is  always  uncolored, 
though  its  hardness  is  7.  From  garnet  it  may  be  distin- 
guished by  the  spec,  grav.,  garnet  being  very  little  more 
than  3,  seldom  ever  over  4,  and  its  streak  is  white.  But 
the  blowpipe  will  determine  the  difference  immediately, 
and  this  must  be  brought  in  to  help. 

BEFORE  THE  BLOWPIPE.  As  cassiterite,  on  charcoal  and 
alone,  it  remains  unchanged.  With  soda  it  is  reduced  to  a 
malleable  metallic  tin  globule,  and  leaves  a  white  coating 
(around  the  metal)  of  tin  oxide.  With  borax  on  the  plati- 
num loop,  it  gives  the  colors  of  iron  and  maganese  if  they 
be  present.  The  former  is  almost  always  present,  but  some- 
times in  quantities  as  low  as  1  per  cent.  But  pure  tin  in 
the  borax  gives  no  color;  the  borax  bead,  if  discolored  at  all, 
shows  the  presence  of  other  metals,  as  iron,  copper,  manga- 
nese, especially  in  stannite.  It  will  therefore  be  very  diffi- 
cult to  distinguish  the  color  and  shades,  since  they  become 
mixed ;  the  skilful  method  is  to  begin  with  a  mere  speck  of 
the  assay  and  turn  on  the  O.  F.  and  then  add  a  little  more, 
watching  the  bead  with  great  care,  as  frequently  certain  tints 
will,  in  the  progress  of  oxidation,  reveal  themselves  to  skilful 


180  MINERALS,   MINES,   AND   MINING. 

manipulation  as  they  will  not  when  a  larger  quantity  is 
used  at  first.  However,  for  detection  of  the  associated  iron, 
copper,  or  manganese,  resort  must  be  had  to  chemical  test. 
The  best  flux  is  one  of  equal  parts  of  borax,  or  sodium  car- 
bonate, and  cyanide  of  potassium,  upon  the  charcoal  before 
the  I.  F.  of  the  blowpipe. 

As  stannite,  in  small  pieces  in  a  glass  tube  closed  at  the 
lower  end,  it  decrepitates  under  heat  and  gives  off  a  little 
sublimate  (tin  oxide) ;  in  an  open  tube  it  gives  off  the  smell 
of  sulphur  (sulphurous  acid,  sulphurous  dioxide)  and  a  white 
cloud  of  oxide  of  tin  near  the  assay  upon  the  glass.  On 
charcoal  it  fuses,  gives  off  sulphur,  and  the  white  tin  oxide 
appears  on  the  charcoal.  It  may  be  decomposed  by  nitric 
acid,  and  the  solution  (blue)  shows  the  copper,  but  the  sul- 
phur and  oxide  of  tin  are  apparent  as  precipitates. 

The  geology  of  this  ore  is  evidently  that  of  the  earliest 
rocks,  granite,  gneiss,  chlorite,  porphyry,  and  where  it  occurs 
in  Banca  in  the  alluvial  soil  it  seems  to  have  descended  from 
the  granite  ranges.  It  occurs  in  veins,  and  in  Cornwall  they 
run  almost  always  east  and  west.  (Makins.)  In  Dakota  it 
is  found  in  mica  schist  mixed  with  feldspar  in  the  granitic 
regions,  as  we  have  already  described.  In  other  places  in 
quartz  through  granite  and  the  earlier  rocks. 

EXTRACTION  for  detection.  From  the  cassiterite  (binoxide) 
or  tinstone,  it  may  be  extracted  in  a  small  way  by  melting 
100  grains  with  20  grains  of  dry  carbonate  of  soda  and  20 
to  25  grains  of  borax  in  a  brasqued  crucible.  (See  p.  77.) 

In  the  larger  way  and  as  impure,  or  stannite,  as  when 
combined  with  sulphur,  copper,  arsenical  pyrites,  etc.,  it  is 


TIN.  181 

broken  into  small  pieces  and  separated  from  quartz  and 
lighter  gangue  by  washing,  that  is  concentrating,  on  an 
incline,  as  the  tin  ore  is  much  heavier  than  the  usual  gangue 
material.  It  is  then  roasted  under  a  low  red  heat  to  expel 
sulphur,  arsenic,  etc.,  the  iron  is  left  as  an  oxide  (sesqui- 
oxide),  and  the  copper  as  a  sulphate  with  some  unaltered 
sulphide  of  copper.  To  further  desulphurize  the  unaltered 
sulphide  it  is  moistened  with  water  and  exposed  to  the  air 
for  some  days,  after  which  the  whole  of  the  copper  may  be 
removed  by  washing,  as  the  copper  sulphate  is  readily  dis- 
solved. The  iron  may  now  be  also  separated  by  washing,  as 
it  is  a  lighter  sesquioxide  and  is  in  suspension.  The  ore 
now  contains  about  65  per  cent,  tin,  and  it  is  mixed  very 
intimately  with  about  J  of  powdered  coal  and  a  little  lime,  or 
fluorspar  to  form  a  fusible  slag  with  the  earthy  impurities, 
gradually  roasted  to  prevent  the  melting  of  the  tin  oxide  with 
the  silica  to  form  a  silicate,  from  which  the  metal  would  be 
reduced  with  difficulty.  (Bloxam.)  If  the  process  is 
conducted  in  a  crucible,  the  latter  must  be  covered  so  as  to 
exclude  the  air  and  favor  the  combination  of  the  carbon  and 
tin  oxide,  its  oxygen  going  over  to  the  carbon  to  form 
carbonic  oxide  (carbon  monoxide).  This  process  requires  a 
low  red  heat  for  6  to  8  hours,  and  then  the  tin  is  found 
beneath  the  slag. 

The  tin  thus  extracted  contains  some  impurities,  as  iron, 
copper,  arsenic,  sometimes  tungsten  and  wolfram  (tungstate 
of  iron  and  manganese),  and  in  the  large  way  it  is  purified 
from  the  latter  substance  before  melting,  by  fusion  with 


182  MINERALS,   MINES,    AND   MINING. 

carbonate  of  soda  in  the  reverberatory  furnace,  thus  convert- 
ing the  tungstic  acid  into  a  soluble  tungstate  of  soda,  which 
is  dissolved  out  by  water  and  crystallized  for  sale  to  the  calico 
printers. 

In  estimating  the  QUANTITY  of  tin  in  any  compound,  it  is 
done  by  reducing  the  tin  to  metastannic  acid  (Sn5O10),  for 
in  this  form  it  may  be  separated  from  almost  all  the  other 
metals.  This  acid  appears  as  a  white  crystalline  hydrate, 
when  tin  is  oxidized  by  nitric  acid,  and  the  process  is  as  fol- 
lows :  A  nitric  acid  solution  is  made  and  then  evaporated  to 
a  very  small  bulk ;  by  this  the  dioxide  of  tin  is  thoroughly 
separated.  Proceed  by  washing  this  precipitate  well  with 
dilute  nitric  acid,  and  afterward  by  water.  After  which  it 
is  dried  and  heated  to  a  low  red  to  drive  off  the  water,  for 
when  dried  by  exposure  it  has  the  composition  Sn5O10  -f 
10H2O,  but  when  heated  to  212°  F.  it  becomes  Sn6O10  + 
5H2O.  If  more  strongly  heated,  it  assumes  a  yellowish 
color  and  a  hardness  resembling  powdered  tinstone  (SnO2). 
Now,  to  estimate  the  quantity  of  tin,  this  residue  is  weighed 
and  the  proportion  is  78.66  of  tin  to  every  one  hundred 
parts.  According  to  Fresenius,  78.67  of  Sn,  21.33  O2  = 
100.00. 

When  lead  is  present  and  it  is  necessary  to  decide  the 
amount  of  that  metal,  it  is  necessary,  after  dissolving  the 
compound  in  somewhat  diluted  nitric  acid  under  heat,  to 
dilute  and  filter  and  wash  out  the  metastannic  acid  as  above, 
and  then  to  the  residue  add  sulphuric  acid  in  excess  and 
evaporate  all  down  to  expel  the  nitric  acid.  This  causes 
the  precipitation  of  the  lead  sulphate  which  is  filtered  out, 


ZINC.  183 

washed  and  removed  to  a  porcelain  crucible,  the  filter  paper 
(which  contains  some  remains  of  the  sulphate)  is  burned  on 
the  crucible  cap,  or  in  another  porcelain  crucible,  till  it 
ceases  to  decrease  in  weight ;  this  weight  may  be  added  to 
the  contents  of  the  other  crucible,  and  then  all  heated  till 
no  decrease  of  weight  is  found — then  weighed  and  the 
amount  of  lead  determined  from  the  sulphate  of  lead  ;  of  the 
latter  68.31  parts,  by  weight,  are  lead  in  every  100  parts  of 
sulphate. 


ZINC. 

OCCURRENT  FORM.  It  is  not  proved  that  it  has  ever  oc- 
curred native,  although  so  stated. 

HARDNESS,  of  metallic  zinc,  2. 

GRAVITY,  of  metallic  zinc,  7.69  (Bloxam),  or  7.146 
(Makins),  7.2  (Richter). 

COLOR.  Grayish  or  slightly  bluish  white,  for  the  METAL  ; 
for  the  ores  see  further  on. 

DUCTILITY,  brittle,  both  at  ordinary  temperature  and  at 
high  temperature,  400°  F.,  but  in  1812  it  was  discovered 
that  a  temperature  between  200°  and  250°  F.,  but  more 
recent  experiments  give  212°  and  302°  F.,  rendered  it  mal- 
leable and  capable  of  being  rolled  into  thin  sheets.  For  this 
purpose  it  is  necessary  that  the  zinc  should  not  contain 
iron  or  lead,  the  former  of  which  it  acquires  when  melted  in 
iron  pots,  while  the  lead  is  carried  over  in  the  distillation  of 
the  zinc  in  consequence  of  the  presence  of  galena  (sul- 
phide of  lead)  in  the  ore. 


184  MINERALS,   MINES,   AND    MINING. 

MELTING  POINT,  770°  F.  (773°,  Bloxam  and  Miller). 

IMPURITIES.  Metallic  zinc,  as  occurring  in  commerce,  fre- 
quently contains,  as  above  stated,  iron  and  sometimes  lead, 
but  also  cadmium,  tin,  antimony,  arsenic,  and  copper.  (Blox- 
am.) Carbon  is  also  mentioned  among  its  impurities,  but 
Elliot  and  Storer  did  not  find  it  in  any  of  the  thirteen  speci- 
mens they  examined,  although  traces  of  sulphur  were  always 
present. 

LOCALITIES.  The  ores  of  zinc  are  found  in  Silesia  as  cala- 
mine  (zinc  carbonate) ;  Carinthia,  electric  calamine  (zinc 
silicate) ;  in  Belgium  (zinc  carbonate)  ;  in  the  Mendip  Hills, 
Somersetshire,  Cumberland  and  Derbyshire  (zinc  carbon- 
ate) ;  blende  (zinc  sulphide)  is  worked  in  England. 

United  States.  In  New  Jersey  as  red  oxide  of  zinc  ;  Sau- 
con  Valley,  Penn.,  as  silicate  and  carbonate  of  zinc  ;  "  Smith- 
sonite"  or  carbonate  of  zinc,  Ueberoth  mine  near  Bethlehem, 
Penn. ;  abundant  as  an  ore  ;  at  the  same  place  a  pale  yellow 
zinc  bearing  clay  is  found.  Also  in  Illinois  (Collinsville, 
Peru,  and  La  Salle)  ;  Missouri,  Kansas,  and,  Arkansas,  and 
in  recent  borings  (1887)  at  200  feet  depth. 

It  frequently  happens  that  ZINC  SULPHIDE  is  found  in  amber- 
colored  streaks  and  isolated  small  pieces  in  places  where  no 
zinc  mines  will  probably  ever  be  found.  It  has  been  ob- 
tained in  such  small  quantities  by  the  author,  in  the  Niagara 
rocks  at  Niagara  Falls ;  also  in  Ohio  in  the  Helderberg 
limestone,  on  the  Cincinnati  and  Marietta  Railroad  near 
Greenfield,  and  in  various  other  places.  The  silicates  and 
carbonates  are  the  most  useful  ores. 


ZINC.  185 

The  SILICATE  (Willemite)  appears  generally  yellow  and 
gray,  but  sometimes  green  and  even  pink.  Hardness,  5.5  ; 
grav.,  3.8  to  4.1.  Streak,  uncolored.  If  pure  it  should 
contain  72.9  per  cent,  zinc  oxide. 

CARBONATE  OF  ZINC  (Smithsonite)  has  a  hardness  of  5  ; 
grav.,  4  to  4.5,  containing  about  64  per  cent,  of  zinc  oxide, 
when  pure  64.8.  It  has  a  color  varying  from  white  to  gray, 
also  greenish  and  brownish-white,  translucent  and  brittle. 
It  is  found  in  Missouri  and  Arkansas  along  with  the  lead 
ores  in  the  lower  Silurian  limestone. 

ZINC  SULPHIDE,  or  BLENDE,  is  translucent,  having  a  honey 
color  by  transmitted  light,  though  frequently  a  vitreous  and 
almost  metallic  appearance  by  reflected  light.  Another 
name,  mineralogical,  is  Sphalerite.  Hardness,  3.5  to  4; 
grav.,  about  4.  It  rarely  appears  black,  reddish,  or  green. 
Streak,  white  to  reddish-brown ;  always  brittle  and  translu- 
cent, sometimes  transparent.  Of  zinc  sulphide  the  propor- 
tions are  :  Zn,  65.06  ;  S,  32  =  97.06;  per  cent.,  Zn,  67.03 ; 
S,  32.97  =  100.00;  Zn,  64.9  (Richter),  65.06  (Fresenius). 

UNDER  THE  BLOWPIPE,  BLENDE  on  charcoal  in  the  R.  F. 
gives  a  coating  of  white  oxide  of  zinc,  yellow  while  hot, 
white  when  cold.  The  mineralogist  should  remember  that 
the  fact  that  zinc  oxide  is  yellow  while  hot,  white  when  cold, 
is  not  always  an  exclusive  proof  of  zinc,  as  monazite  acts  so 
also,  whose  composition  in  part  is  phosphoric  acid,  cerium, 
lanthanum,  but  no  zinc,  but  very  rare,  though  found  in  the 
United  States ;  it  also  presents  an  enamel  white  glass,  much 
like  zinc  on  flaming  in  borax,  although  zinc  silicate  does 
this  without  borax  and  alone.  It  is  called  monazite  from  a 


186  MINERALS,   MINES,   AND   MINING. 

Greek  word,  "solitary"  because  of  its  rare  occurrence. 
Perhaps  the  similarity  of  change  under  the  blowpipe  may 
be  due  to  cerium,  which  with  borax  in  the  O.  F.  also  gives1 
a  yellow  turning  nearly  colorless  when  cold,  as  in  the  min- 
eral cerite ;  but  these  are  so  rare  that  they  only  need  mention. 
With  a  cobalt  solution  the  coating  in  O.  F.  gives  a  green 
color.  In  open  tube  it  gives  off  sulphurous  fumes  and  gen- 
erally changes  its  color. 

CARBONATE  OF  ZINC,  Smithsonite,  in  the  closed  tube  gives 
off  carbonic  dioxide,  CO2,  and  if  pure  is  yellow  while  hot  and 
colorless  while  cooling.  On  charcoal  with  soda  acts  as 
blende.  If  cadmium  is  present,  it  gives  a  deep  yellow  or 
brown  coating  before  the  zinc  coating  appears.  (Dana.) 
It  is  soluble  in  hydrochloric  acid  and  effervesces.  If  cop- 
per, iron,  and  manganese  are  present,  they  severally  give 
their  own  reactions,  and  great  care  must  be  exercised  if 
even  two  of  these  are  present.  Iron  may  be  detected  by 
first  putting  half  a  drop  of  nitric  acid  on  the  assay  and 
afterward  an  equally  small  amount  of  solution  of  ferrid- 
cyanide  of  potassium,  producing  a  blood-red  color.  Copper 
must  be  tested  in  the  wet  way,  as  we  have  indicated  under 
that  metal,  as  also  must  manganese. 

SILICATE  OF  ZINC  (Willemite).  This  must  be  held  by  for- 
ceps (in  a  small  piece)  in  the  O.  F.  and  then  it  fuses  with 
considerable  difficulty,  making  a  white  enamel.  On  char- 
coal, either  with  or  without  soda,  in  the  I.  F.  it  gives  the 
white  coating  exactly  as  in  blende  and  acts  with  cobalt  so- 
lution in  the  same  way. 


ZINC. 


187 


Fig.  6. 


DISTILLING  ZINC.  For  chemical  purposes  it  is  essential 
that  the  zinc  be  distilled,  which  may  be  done  in  the  follow- 
ing way,  on  a  small  scale,  as  recom- 
mended by  Bloxam  :  Take  a  small 
black  lead  crucible,  J.,  about  five  inches 
high  and  three  in  diameter.  A  hole  is 
drilled  through  the  bottom  with  a  round 
file,  and  into  this  is  fitted  a  piece  of 
wrought  iron  gas-pipe,  B,  running  up  in 
the  crucible  above  the  zinc ;  the  piece 
may  be  nine  inches  long  and  one  inch  in 
diameter.  Any  crevices  between  the 
pipe  and  the  sides  of  the  hole  are  carefully  stopped  up  with 
fire-clay  moistened  with  solution  of  borax.  A  few  ounces 
of  zinc  are  introduced  into  the  crucible,  the  cover  of  which 
is  then  carefully  cemented  on  with  the  same  kind  of  fire- 
clay with  borax  solution  until  all  is  tight.  Keep  the  cruci- 
ble several  hours  in  a  warm  place  till  all  is  perfectly  dry. 
It  is  then  placed  in  a  cylindrical  furnace  with  a  hole  in  the 
bottom,  through  which  the  iron  pipe  may  pass  as  in  Fig.  6. 
A  lateral  opening,  (7,  may  be  made  for  a  tube  connected 
with  a  bellows.  Some  lighted  charcoal  is  thrown  into  the 
furnace  and  when  well  kindled  add  coke  broken  into  small 
pieces.  The  fire  is  then  blown  till  the  zinc  distils  freely 
into  the  vessel  of  water  D.  Four  ounces  of  zinc  may  be 
easily  distilled  in  half  an  hour.  But  for  still  purer  zinc  see 
further  on. 

From  CALAMINE  or  BLENDE  in  the  large  way  by  the  Eng- 
lish method,  the  ore  is  treated   to  a   preliminary  process 


188  MINERALS,   MINES,    AND    MINING. 

which  brings  them  both  to  the  condition  of  oxide  of  zinc. 
For  this  purpose  the  ores  are  calcined  in  a  reverberator?  fur- 
nace in  order  to  expel  the  carbonic  dioxide,  but  the  blende 
is  roasted  for  ten  or  twelve  hours,  with  constant  stirring,  so 
as  to  expose  fresh  surfaces  to  the  air,  when  the  sulphur 
passes  off  in  the  form  of  sulphurous  acid  and  its  place  is 
taken  by  the  oxygen,  the  ZnS  becoming  ZnO.     The  extrac- 
tion of  the  metal  from  this  oxide  of  zinc  depends  upon  the 
circumstance  that  zinc  is  capable  of  being   distilled  at  a 
bright  red  heat,  its  boiling-point  being  1904°  F.     (Bloxam.) 
This  oxide  is  mixed  with  about  half  its  weight  of  coke  or 
anthracite  coal  and  introduced  into  large  crucibles  with  a 
hole  in  the  bottom  as  in  Fig.  6.     When  the  mixture  in  the 
crucibles  is  heated  to  redness  it  begins  to  evolve  carbonic 
monoxide,  produced  by  the  combination  of  the  carbon  with 
the  oxygen  from  the  oxide  of  zinc.     This  gas  burns  with  a 
blue  flame  at  the  mouth  of  the  iron  pipe,  but  at  a  bright 
red  heat  the  metallic  zinc  which  has  been  thus  liberated  is 
converted  into  vapor,  and  the  greenish-white  flame  of  burn- 
ing zinc  is  perceived  at  the  orifice.     When  this  is  the  case 
about  eight  feet  of  iron  pipe  are  joined  on  to  the  short  piece 
in  order  to  condense  the  vapor  of  zinc,  which  falls  into  the 
vessel  prepared  for  its  reception.     The  distillation  from  cru- 
cibles of  about  four  feet  high  by  two  and  a  half  feet  wide 
occupies  about  sixty  hours,  and  the  average  yield  is  about  35 
parts  of  zinc  from   100  of  ore,  a  considerable  quantity  of 
zinc  being  left  behind  in  the  form  of  silicate  of  zinc  (electric 
calamine)  which  is  not  reduced  by  distillation  with  carbon. 
This  zinc,  however,  is  impure  and  it  is  therefore  melted 


ZINC.  189 

again  in  a  large  iron  pan  and  allowed  to  rest,  in  order  that 
the  dross  may  rise  to  the  surface ;  this  is  skimmed  off,  to  be 
worked  over  again  in  a  fresh  operation  and  the  metal  is  cast 
into  ingots. 

In  the  Belgian  process  the  zinc  oxide  is  placed  in  fire- 
clay cylinders  lying  horizontally,  the  vapor  being  conveyed  by 
a  short  conical  iron  pipe,  the  smaller  end  projecting  out  from 
the  cylinder  and  communicating  with  another  conical  iron 
receiver  at  its  smaller  end,  and  this  is  emptied  every  two 
hours  into  a  large  ladle.  This  method  economizes  fuel. 

In  the  Silesian  process  the  vapors  are  received  into  a  short 
clay  pipe  instead  of  iron  and  it  is  remelted  in  clay  pots  and 
hence  has  less  iron  in  the  reduced  zinc,  as  melted  zinc 
always  dissolves  iron  and  a  very  small  quantity  of  iron  is 
found  to  injure  zinc  when  required  for  rolling  into  sheets. 
A  small  quantity  of  lead  always  distills  over  together  with 
the  zinc  and  therefore  it  is  sometimes  remelted  near  the 
base  of  a  flue  in  a  kind  of  pocket  or  small  pit,  for,  since  the 
gravity  of  lead,  11.4,  is  greater  than  that  of  zinc,  6.9,  the 
latter  rises  to  the  surface  and  is  drawn  off,  thus  relieving 
the  mixture  of  some  lead. 

OXIDE  OF  ZINC  when  pure  is  always  white,  but  in  the  im- 
pure results  from  roasting,  etc.,  it  is  of  varied  colors  accord- 
ing to  the  nature  of  the  impurity.  The  true  color  of  pure 
sulphide  of  zinc  is  also  white,  and  the  various  shades  of  the 
ore  are  due  to  the  metallic  impurities  which  almost  always 
exist  and  sometimes  to  such  a  degree  that  the  blende  has  a 
black  appearance  and  sometimes  red,  but  even  then  the 
streak  is  almost  always  white,  or  brownish-white. 


190  MINERALS,   MINES,   AND   MINING. 

Proportion  of  metallic  zinc  in  the  oxide  of  zinc  is — 

Zn  65.06  80.26  per  cent. 

O  16.00  19.74    "       " 

81.06  100.00  " 

PURE  METALLIC  ZINC.  Although  by  redistilling,  and  by 
the  use  of  nitre  in  the  crucible,  zinc  is  supposed  to  be  nearly 
pure,  yet  no  process  gives  zinc  free  from  impurities  absolutely 
except  the  wet  process  as  follows :  Dissolve  the  zinc  in  pure 
sulphuric  acid,  thus  soluble  zincic  sulphate  is  formed,  and 
an  insoluble  lead  sulphate,  if  lead  be  present.  Dilute  and 
filter  and  then  sulphuretted  hydrogen  (H2S)  is  to  be  passed 
through  the  clear  solution ;  this  will  throw  down  the  cad- 
mium and  arsenic.  Separate  these  and  then  treat  the  liquid 
with  carbonate  of  ammonia  in  excess,  thus  the  iron  is  pre- 
cipitated ;  if  any  zinc  falls,  redissolve  by  more  carbonate  of 
ammonia.  Then  sodic  carbonate  is  added  to  the  liquid 
filtered  from  the  iron  precipitate ;  this  throws  down  the  zinc 
as  carbonate ;  this  must  now  be  separated,  washed,  and  dried. 
Next  by  igniting  this  in  a  crucible  (porcelain  if  large  enough) 
pure  zincic  oxide  is  obtained,  which,  if  treated,  as  we  have 
said  above,  with  pure  carbon  and  distilled  in  a  porcelain 
retort,  will  yield  absolutely  pure  zinc.  The  carbon  should  be 
made  from  loaf  sugar  (heated  in  a  crucible  out  of  air).  If  any 
carbon  should  be  present,  a  second  distillation  will  free  it  from 
carbon.  The  hydrogen  made  from  this  zinc  is  free  from  all 
arsenic  and  may  be  considered  pure.  It  is  the  only  proper 
zinc  for  volumetric  analysis. 

Zinc  salts  are  not  precipitated  by  H2S  (sulphuretted  hy- 


ZINC.  191 

drogen),  but  a  white  gelatinous  sulphide  is  precipitated  as  a 
hydrate,  from  neutral  or  alkaline  solutions  of  zinc,  by  means 
of  ammonic  hydric  sulphide  (ammonium  sulphide).  This  is 
soluble  in  acids,  and  is  readily  oxidized  by  contact  with  the 
air.  (Makins.)  In  regard  to  this  method  the  following 
should  be  remembered  and  acted  upon.  Colorless  ammo- 
nium sulphide  precipitates  dilute  solutions  of  zinc,  but  only 
slowly;  yellow  ammonium  sulphide  (see  Reagents)  does 
not  precipitate  dilute  solutions  of  zinc  at  all.  (Fresenius.) 
Ammonium  chloride  favors  the  precipitation  considerably. 
Free  ammonia  acts  to  retard  the  precipitation.  With  care 
and  the  above  suggestions  acted  upon,  zinc  may  be  precipi- 
tated from  a  solution  containing  only  the  one-millionth 
part.  The  filtrate  from  zinc  sulphide  is  likely  to  be  turbid. 
The  washing  is  best  conducted  with  water  having  a  small 
quantity  of  ammonium  sulphide,  and  continually  diminished 
quantities  of  ammonium  chloride,  but  entirely  omitted  at 
last.  The  hydrated  zinc  sulphide  is  insoluble  in  water, 
caustic  alkalies,  alkaline  carbonates,  and  the  monosulphides 
of  the  alkali  metals.  It  dissolves  readily  and  completely  in 
hydrochloric  and  nitric  acids,  and  sparingly  in  acetic  acid. 
When  air-dried  its  composition  is  3ZnS  -f  2H2O ;  dried  at 
100°  C.  (212°  F.)  2ZnS  +  H2O;  at  150°  C.  (302°  F.)  4ZnS  + 
H2O.  On  ignition  it  loses  all  its  water,  but  the  ignition 
must  not  be  continued  longer  than  five  minutes,  nor  over 
a  gas  blowpipe  (Fresenius),  or  loss  will  result. 

If,  in  the  analysis  of  zinc  ore,  the  cadmium  and  arsenic 
are  to  be  separated,  they,  as  well  as  all  other  metallic  oxides 
of  Groups  V.  and  VI.,  may  be  separated  thus:  Precipitate 


192  MINERALS,   MINES,    AND   MINING. 

the  acid  solution  of  the  two  (cadmium,  oxide  of,  Group  V. 
from  arsenic  oxide  of  Group  VI.)  with  hydrogen  sulphide, 
taking  care  in  the  cadmium  and  arsenic  separation  to  have 
as  little  acid  in  excess  as  possible.  The  precipitates  consist 
of  the  sulphides  of  all  the  metals  of  Groups  V.  and  VI. 
Wash  and  treat  at  once  with  yellow  ammonium  sulphide  in 
excess.  It  is  usually  best  to  spread  the  filter  paper  with  the 
precipitates  in  a  porcelain  dish,  add  the  ammonium  sulphide, 
cover  with  a  glass,  and  place  all  upon  a  sand-bath,  or  water- 
bath  heated,  not  exposing  to  the  air.  Add  some  water, 
filter  off  the  clear  liquid,  treat  the  residue  again  with  some 
ammonium  sulphide,  digest  a  short  time,  repeat  the  same 
operation  perhaps  a  third  or  fourth  time,  filter  and  wash  the 
remaining  sulphides  of  Group  V.  (lead,  copper,  cadmium) 
with  water  containing  ammonium  sulphide.  If  tin  sulphide 
be  present,  the  ammonium  sulphide  must  be  very  yellow  or 
some  flowers  of  sulphur  must  be  added  to  the  ammonium 
sulphide.  If  copper  be  present,  it  is  best  to  use  sodium  sul- 
phide rather  than  ammonium  sulphide,  as  copper  sulphide 
is  somewhat  soluble  in  ammonium  sulphide.  But  if  mercury 
is  present  sodium  sulphide  cannot  be  used,  as  mercury  sul- 
phide is  soluble  in  sodium  sulphide,  but  this  latter  presence 
(of  mercury)  is  not  to  be  suspected,  as  no  such  occurrence 
has  yet  been  met  with  in  ores. 

Add  now  to  the  alkaline  filtrate,  gradually,  hydrochloric 
acid  in  small  portions  until  the  acid  predominates  ;  let  it  sub- 
side and  filter  off  the  sulphides  of  Group  VI.  If  it  is  known 
that  a  large  quantity  of  arsenic  is  present  with  a  small  amount 
of  copper,  bismuth,  etc.,  the  latter  may  be  precipitated  by 


ZINC.  193 

a  brief  treatment  with  hydrogen  sulphide  which  may  also  pre- 
cipitate a  little  of  the  arsenious  sulphide.  Filter,  extract  by 
dissolving  the  precipitate  with  a  little  ammonium  (or  potassi- 
um) sulphide,  acidify  the  solution  and  mix  it  with  the  former 
solution  containing  the  larger  amount  of  arsenic,  and  proceed 
to  treat  further  with  hydrogen  sulphide,  heating  the  liquid  to 
about  150°  F.  as  long  as  any  precipitate  comes  down;  in  the 
mixture  will  always  be  some  sulphur  with  the  arsenious  sul- 
phide (if  that  is  all  that  is  present),  since  the  arsenic  acid  is 
first  reduced  to  arsenious  acid  (with  separation  of  sulphur) 
and  then  the  latter  is  decomposed.  (Rose.)  To  convert  this 
mixture  into  pure  arsenious  sulphide  ready  for  weighing, 
treat  it  as  follows :  Extract,  by  dissolving  with  ammonia,  the 
washed  and  still  moist  precipitate  in  the  filter,  wash  the 
residual  sulphur,  precipitate  the  solution  with  hydrochloric 
acid,  cold,  filter,  dry,  extract  any  admixed  sulphur  by  dis- 
solving it  out  and  through  the  filter  by  adding  purified  car- 
bon disulphide,  dry  at  212°  F.  (100°  C.)  and  weigh.  The 
results  are  accurate.  (Fresenius.)  Arsenious  sulphide  forms 
a  precipitate  of  a  rich  yellow  color,  it  is  insoluble  in  water, 
except  as  one  part  to  about  one  million  of  water,  and  .also 
in  hydrogen  sulphide  water,  it  may  be  dried  at  212°  F. 
(100°  C.)  without  decomposition.  Red  fuming  nitric  acid 
converts  it  into  arsenic  acid  and  sulphuric  acid.  Composi- 
tion, As2S3; 

As2  150  60.98  per  cent. 

S3  96  39.02    «      " 

246  100.00 

13 


194  MINERALS,   MINES,   AND   MINING. 


LEAD. 

LEAD  is,  in  some  very  rare  cases,  said  to  have  been  found 
native  in  globules,  or  small  scales,  but  of  no  practical  value. 
In  HARDNESS  it  is  1.5;  GRAVITY,  when  pure,  11.445  (Dana), 
11.35  (Makins);  its  order  in  ELECTRICAL  CONDUCTING  POWER  is 
8,  silver  being  1,  copper  2,  gold  3.  HEAT-CONDUCTING  POWER  9, 
among  the  metals  (1)  silver,  (2)  gold,  (3)  copper,  (4)  alu- 
minum, (5)  zinc,  (6)  iron,  (7)  tin,  and  (8)  platinum.  And  in 
MALLEABILITY  it  ranges  10 ;  DUCTILITY  12 ;  TENACITY  11,  when 
in  addition  to  the  above-mentioned  metals  we  add  palladium, 
cadmium,  and  nickel.  FUSIBILITY  617°  F.  (325°  C.). 

The  only  abundant  lead  ore  is  GALENA,  mineralogical 
name  galenite,  a  lead  gray  brittle  ore,  described  hereafter, 
but  it  occurs  in  various  associations  as  carbonate,  phosphate, 
arsenate,  and  sulphate,  rarely  worked  as  ores.  As  a  mineral 
it  is  found  as  antimonate,  chloride,  oxide,  tungstate,  molyb- 
date,  vanadate,  chromate,  seleniate,  and  in  some  very  rare 
and  unimportant  forms.  The  only  practical  advantage  in 
examining  these  rarer  forms  is  that  it  may  lead  to  the  dis- 
covery of  the  useful  ores,  and  hence  under  the  blowpipe  we 
have  described  the  action  of  these  lead  compounds  as  a  class. 

The  GEOLOGICAL  HORIZONS  and  OCCURRENCE  of  lead  are, 
specially  galena,  in  limestones  of  the  Lower  Silurian  era, 
especially  the  Trenton,  also  in  millstone  grit.  .  It  is  asso- 
ciated frequently  with  zinc  (blende),  iron  and  copper  pyrites, 
also  with  calcite,  as  in  New  York  State.  Its  form  and  cleav- 


LEAD.  195 

age  (as  galena)  are  generally  cubical,  rarely  octahedral  in  the 
United  States,  but  frequently  in  England. 

It  is  found  in  extensive  deposits  in  Illinois,  Iowa,  Missouri, 
Kansas,  Wisconsin,  and  in  New  York  and  New  England, 
also  in  Pennsylvania,  Virginia,  Tennessee,  Michigan,  but 
chiefly  in  Colorado  (Leadville),  where  141,450  tons  of  ore 
were  produced  in  1883,  Utah,  Nevada,  Idaho;  besides  these 
there  are  many  individual  producers  turning  out  more  than 
2000  tons  of  ore  a  year,  not  mentioned  in  the  above  account. 
New  Mexico  turned  out  6000  short  tons  of  lead  in  1884, 
and  Arizona  2700  in  the  same  year.  Large  quantities  of  lead 
are  produced  in  the  working  of  silver  leads,  for  it  is  thought 
that  no  galenas  are  found  without  silver,  although  one  author 
says : — 

"  We  keep  two  hand-specimens  as  special  curiosities. 
Both  are  from  Northern  Lake  Superior  and  look  exactly 
alike.  One  of  them  contains  silver,  $4500  to  the  ton ;  the 
other  contains  none.  There  is  very  little  earthy  matrix  in 
either  case ;  but  in  the  former  it  is  carbonate  of  lime,  in  the 
latter  it  is  silex  or  quartz." 

Then,  again,  a  galena  in  calcareous  spar  from  this  same 
region  showed  the  faintest  trace  of  silver.  In  one  instance 
a  sulphide  of  zinc  and  lead  from  the  north  side  of  Thunder 
Bay,  Lake  Superior,  yielded  $4600  per  ton.  In  another, 
not  far  off,  a  silicious  rock  With  carbonate  of  lime  and  sul- 
phide of  silver  gave  $360  per  ton.  In  addition  to  silver  all 
the  galena  leads  contain  more  or  less  gold.  Percy  says  that 
he  has  never  found  a  lead  ore  which  did  not  contain  gold. 
It  contains,  however,  in  some  cases  not  more  than  half  an 


196  MINERALS,   MINES,   AND   MINING. 

ounce  of  gold  to  the  ton  even  where  the  amount  of  silver 
was  1138  ounces  to  the  ton. 

Galena  is  a  crystalline  ore,  its  primary  form  being  the 
cube,  and  sometimes  with  very  bright  metallic  lustre.  But 
it  often  occurs  in  small  quantities  in  various  associations, 
where  it  is  useless  to  expend  any  money  in  attempting  to 
work  it. 

WORKING  ON  THE  LARGE  SCALE.  Before  smelting,  the  ore  is 
assayed  to  find  out  the  amount  of  lead  present.  And  the 
simplest  method  is  by  simply  fusing  the  ore  in  contact  with 
iron,  the  sulphur  of  the  ore  uniting  with  the  iron  to  form  a 
sulphide.  The  simplest  way  is  to  use  a  wrought-iron  cruci- 
ble, or  when  that  may  not  be  had  to  use  a  clay  crucible 
and  introduce  wrought-iron  pieces  (nails,  strips,  etc.)  into 
the  melted  sulphide.  The  fluxes  used  are  some  alkaline 
ones  for  the  dissolving  and  separation  of  earthy  matters  and 
a  little  borax.  Supposing  an  earthen  crucible  is  employed, 
the  ore  is  first  powdered  and  dried.  The  weight  for  assay  is 
then  taken  and  250  grains  is  a  fair  quantity  to  operate  upon, 
but  if  the  ore  is  not  rich  as  much  as  500  grains  must  be 
taken.  With  250  grains,  350  grains  of  black  flux,  or  some 
analogous  flux,  for  example,  a  part  of  powdered  argol  with 
7  of  sodic  carbonate,  and  of  this  mixture  about  150  grains 
might  be  used.  A  clay  crucible  having  been  heated  to  dull 
redness  the  mixture  is  introduced ;  about  50  grains  more 
flux  is  now  put  in,  then  a  few  pieces  of  good  iron  (horse- 
shoe nails^are  considered  excellent).  Lastly,  about  60  or  70 
grains  of  fused  borax  are  put  upon  the  top  of  all.  Of  course 
if  500  grains  are  used  the  proportions  would  be  accordingly 


LEAD.  197 

increased.  The  crucible  is  then  placed  in  a  wind  furnace 
and  heated  gradually  to  full  redness  for  about  ten  minutes, 
after  which  the  remaining  iron  is  removed,  the  whole  al- 
lowed to  cool,  when  the  pot  is  broken  and  the  mass  struck 
a  sharp  blow  on  the  side  with  a  hammer ;  this  compresses 
the  button  and  breaks  the  slag,  detaching  it.  Or,  if  all  can 
be  poured,  it  may  be  poured  into  a  mould  with  care  that  no 
metal  remains  adhering  to  the  crucible.  An  iron  crucible  or 
deep  dish  of  iron  is  thought  to  be  better ;  in  such  a  case  no 
strips  of  iron  or  nails  are  used.  A  dry  assay  may  be  made 
without  iron  in  the  following  way  :  The  dried  and  weighed 
assay  is  mixed  with  three  or  four  times  its  weight  of  dry 
potassic  carbonate.  This  is  put  into  a  small  clay  crucible 
and  covered  with  a  layer  of  dry  common  salt.  It  is  next 
introduced  into  a  muffle  and  heated  to  a  high  temperature 
for  half  an  hour.  A  button  of  lead  will  subside,  which  on 
removal  of  the  slag  may  be  weighed.  But  this  requires 
more  attention  and  time  than  the  iron  method. 

IN  THE  WET  METHOD  the  lead  may  be  converted  into  the 
sulphate  thus :  Powder  the  ore,  dry  and  weigh  off  twenty- 
five  grains.  This  is  treated  with  strong  nitric  acid.  When 
decomposition  ceases  a  few  drops  of  strong  sulphuric  acid 
are  added,  and  it  is  to  be  evaporated  until  all  the  nitric  acid 
is  driven  off.  This  may  be  done  in  an  evaporating  porcelain 
dish  on  the  sand-bath.  The  metal  will  thus  be  converted 
into  sulphate.  The  mass  is  next  digested  in  water  to  dis- 
solve out  soluble  sulphates,  and  the  insoluble  residue  filtered 
out  and  washed  with  water  containing  a  little  sulphuric  acid. 
The  insoluble  matter  is  next  dried,  ignited  in  a  small  porce- 


198  MINERALS,  MINES,  AND  MINING. 

lain  crucible  and  weighed.  It  is  next  removed  and  digested 
in  a  solution  of  tartrate  of  ammonia  or  of  acetate  of  am- 
monia, added  in  successive  portions ;  this  will  dissolve  out 
the  plumbic  (lead)  sulphate,  leaving  any  baric  sulphate  with 
other  insoluble  bodies,  as  the  oxides  of  tin  and  antimony, 
quartz,  etc.  The  part  undissolved  of  the  whole  is  again 
filtered  out  and  well  washed  with  boiling  water,  and  again 
dried,  ignited,  and  weighed.  The  difference  between  the 
two  weighings  is  the  amount  of  plumbic  sulphate  which  was 
present  in  the  first  weighed  matter  and  from  this  the  weight 
of  lead  may  be  calculated.  The  composition  of  lead  sul- 
phate is — 

PbO  223  73.60  per  cent. 

SO3  80  26.40    «       " 

303  100.00    "       " 

Of  the  PbO  92.83  per  cent,  is  lead  or  68.32  per  cent,  of 
lead  sulphate. 

The  quantity  of  lead  having  been  determined,  the  lead 
ores  are  picked  over,  sorted  to  obtain  the  richest  and  separate 
the  barren  parts ;  it  is  then  crushed,  washed  in  order  to  con- 
centrate, and  then  placed  upon  the  hearth  of  the  reverbera- 
tory  furnace  and  carefully  and  evenly  heated,  not  to  melt, 
but  with  free  access  of  air,  to  change  the  lead  sulphide  into 
lead  oxide  and  sulphate  by  the  oxidation  of  both  the  lead 
and  sulphur  of  the  galena.  The  portions  so  changed  react 
upon  some  unchanged  ore,  and  the  sulphur  and  oxygen 
being  just  in  the  proportions  to  produce  sulphurous  anhy- 


LEAD.  199 

dride  (SO2)  this  gas  is  formed  and  evolved  and  the  metallic 
lead  set  free. 

Where  the  ore  contains  much  silica  this  process  would 
be  attended  with  much  loss  of  lead  from  the  union  of  the 
lead  with  the  silex.  In  this  case  the  process  with  iron 
would  have  to  be  resorted  to. 

The  fumes  or  gaseous  constituents  passing  off  from  lead 
ores  consist  largely  of  arsenious  acid  as  well  as  sulphurous 
anhydride,  and  the  solid  particles  frequently  passing  off  are 
ashes,  carbonaceous  matter,  ferric  oxide,  but  more  important 
are  the  lead  sulphide,  sulphate,  oxide  and  carbonate,  and 
generally  more  or  less  of  silver  or  what  might  be  called  vola- 
tilized lead  compounds.  Besides  the  poisonous  effect  on  the 
atmosphere,  great  loss  occurs,  as  high  in  some  cases  as  one- 
seventh  of  the  product.  (Makins.)  To  prevent  this  loss,  after 
many  experiments,  nothing  seems  yet  so  efficient  as  the  long 
flues  sometimes,  as  in  zinc  works,  running  great  distances. 

Experiments  have  been  made  with  blowers,  or  what  in 
this  case  may  more  properly  be  called  "  exhausters,"  which 
have  proved  worthy  of  mention  because  the  experiments 
have  been  so  far  successful.  The  principle  is  to  draw  the 
air  in  such  volume  through  "  ways"  or  horizontal,  or  wind- 
ing shafts,  or  chambers  by  means  of  these  exhausters,  as  in 
reality  to  take  the  place  of  the  vapor  stack  and  create  a 
strong  draft. 

In  some  experiments  performed  by  means  of  the  Sturte- 
vant  blower,  we  were  not  entirely  successful  because  the 
exhausting  power,  or  even  the  blowing  power,  was  not  suf- 
ficient to  overcome  the  necessary  resistance,  and  while  for 


200  MINERALS,    MINES,   AND   MINING. 

some  very  small  furnaces  it  worked  well,  would  not  act  con- 
tinuously for  larger,  as  we  found  during  experiments  con- 
tinued several  months.  But  the  power  of  the  Roots'  blower 
is  quite  sufficient  to  allow  a  resistance  of  several  pounds  to 
the  inch  and  yet  reserve  sufficient  power  to  force  the  vapors 
to  pass  through  the  resisting  medium  to  the  stack.  In  one 
Western  reducing  works  the  blower  has  been  used  both  as  an 
exhauster  and  blower — taking  the  vapors  from  the  furnaces 
and  driving  them  through  water  into  an  exhaust  chamber. 

Recent  improvements  in  the  Roots'  blower  render  it  very 
likely  that  it  may  be  used  even  in  such  works  as  the  nickel 
furnaces  at  Lancaster,  Pa.,  if  for  no  other  purpose  than  to 
lessen  the  poisonous  qualities  of  the  exhalations. 

As  the  silver  in  lead  ores  remains  pretty  much  the  same 
in  quantity  in  the  metallic  lead  as  in  the  ore  from  which  it 
was  made,  several  processes  have  been  adopted  to  extract  it. 
Formerly  the  lead  of  commerce  contained  much  more  silver 
than  at  the  present  day. 

Mr.  Pattinson  discovered  that  if  we  fuse  lead  containing 
any  considerable  amount  of  silver,  and  then  cool  slowly, 
carefully  stirring  at  the  same  time,  crystals  will  form  in  the 
bath  and  subside  to  the  bottom ;  and,  moreover,  these  will 
be  much  less  rich  in  silver  than  the  original  metal  was.  In 
order  to  make  practical  use  of  this  discovery  in  the  lead 
works,  a  series  of  ten  or  twelve  large  iron  hemispherical  pots 
are  placed  each  over  its  own  furnace  and  the  silver  leads  are 
melted  near  the  middle  pot  first,  stirred  and  slowly  cooled, 
the  crystals  of  lead  removed  to  the  pot  on  one  side  and  the 
richer  lead  to  that  on  the  other,  and  thus  the  silver  is  con- 


LEAD.  201 

tinually  increased  until  in  the  extreme  pot  on  one  end  the 
lead  may  have  only  a  half  ounce  or  little  over  of  silver  to 
the  ton,  while  that  at  the  opposite  end  may  contain  as  high 
as  640  ounces  to  the  ton.  This  is  called  Pattinson's  process. 

But  another  process  is  used  in  the  United  States  for  which 
Mr.  Parkes  obtained  patents  over  thirty  years  ago.  In  his 
process  lead  and  zinc  are  fused  together ;  the  object  being  to 
avail  one's  self  of  the  fact  that  zinc  rises  to  the  surface  carry- 
ing with  it  the  silver  and  the  gold,  and  the  alloy  may  be 
skimmed  off  in  that  condition  as  loaded  with  a  very  large 
part  of  the  noble  metals.  The  skimmed-off  alloy  contains 
zinc,  some  lead  and  nearly  all  the  silver  and  gold,  and  it  is 
then  subjected  to  another  heating  and  the  less  fusible  parts 
separated  from  the  more  fusible  by  a  process  called  liqua- 
tion, and  the  zinc  distilled  off  as  we  have  described  under 
zinc,  and  the  lead  cupelled  as  also  described  under  gold  and 
silver,  and  thus  the  silver  which  carries  all  the  gold  extracted 
pure,  its  gold  excepted. 

In  both  these  processes  much  lead  oxide  results,  and 
this  is  put  by  itself  and  reduced  with  charcoal  in  a 
reverberating  furnace  having  a  bed,  or  hearth,  on  an  in- 
cline towards  a  tap  hole  situated  on  one  side  at  the  back, 
and  raked  over  to  assist  the  reduction,  and  the  fluid  lead  al- 
lowed to  run  from  the  lower  part  into  a  pot  set  outside  and 
then  ladled  out  and  cast  into  pigs. 

In  the  Parkes  process  zinc  is  added  in  the  proportion  of 
about  one  pound  up  to  If  pounds  to  the  ounce  of  silver  in 
the  lead.  It  is  plain  that  the  zinc  should  be  thoroughly 
stirred  in  the  lead  so  as  to  combine  with  the  silver ;  this 


202  MINERALS,    MINES,   AND   MINING. 

causes  so  much  labor  that  the  process  of  driving  steam  into 
the  lead  has  been  adopted  with  great  success.  One  of  the 
improvements  of  Parkes's  process  is  the  use  of  superheated 
steam,  which  acts,  in  addition  to  the  advantage  just  men- 
tioned, as  an  oxidizing  agent  to  the  metals  retained  by 
the  lead ;  the  watery  vapor  being  decomposed,  the  oxygen 
unites  also  with  a  small  part  of  the  lead  and  the  hydrogen 
passes  off.  Percy  says  that  in  examining  the  results  of  the 
working  of  Parkes's  process  which  he  witnessed,  the  lead  left 
retained  10  dwts.  of  silver  per  ton  ;  that  which  had  been 
liquated  retained  55  ozs.  per  ton ;  while  the  zinc  skimmed 
contained  225  ozs.  8  dwts.  per  ton. 

Mr.  H.  O.  Hoffman,  in  the  recent  report  (1885)  upon  the 
mineral  resources  of  the  United  States,  p.  462,  says  that  the 
Parkes  process  is  employed  in  all  the  desilverizing  works  of 
the  United  States  but  one,  and  with  some  improvements  in 
particular  treatments.  The  use  of  steam  for  stirring,  and 
the  use  of  superheated  steam  for  oxidizing  some  of  the  impu- 
rities, were  patented  before  1873  by  Condurie. 

LEAD  CHARACTERISTICS.  Pure  lead  is  soft  enough  to  be 
cut  into  by  the  finger  nail.  The  impurities  of  commercial 
lead  render  it  harder  and  of  lower  specific  gravity,  and  if 
repeatedly  heated  and  pressed  it  gradually  becomes  harder. 
It  shrinks  on  cooling,  is  readily  acted  upon  by  acetic  acid, 
but  not  by  cold  hydrochloric  or  sulphuric  acid,  the  action 
being  very  slight  when  boiled  with  them.  Nitric  acid  dis- 
solves it,  nitric  oxide  being  evolved,  and  the  nitrate  formed, 
the  acid  acts  very  readily  when  diluted. 

Pure  water  containing  air  (that  is,  unboiled  water)  acts 


LEAD.  203 

upon  lead  to  produce  the  carbonate  of  lead  (basic  carbonate), 
and  the  scale  falling  off,  renewed  action  will  take  place 
until  the  lead  is  dissolved,  but  the  presence  of  bicarbonate 
of  lime  prevents  this  dissolution  entirely,  and  the  phosphates, 
sulphates,  and  carbonates  diminish  the  corrosion,  according  to 
Miller  and  Daniell.  Hence  spring  waters  containing  lime 
carbonates  are  inactive  upon  lead,  but  chlorides,  nitrates,  and 
nitrites  are  particularly  injurious,  3  to  4  grains  to  the  gallon 
inducing  solution.  If,  however,  water  is  boiled  so  as  to  expel 
all  air,  it  is  inactive  upon  lead,  although  the  water  may  be 
pure. 

One  part  in  nineteen  hundred  and  twenty  of  lead  in  gold 
will  destroy  to  some  extent  the  coining  qualities  of  gold. 
Platinum  with  its  own  weight  of  lead  becomes  brittle  and 
granular.  Hence  a  platinum  crucible  is  perforated  by  fusing 
lead  in  it. 

Lead  cannot  be  cupelled  from  platinum,  for  as  the  lead 
decreases  the  melting  point  increases  till  the  platinum  con- 
geals with  lead  still  remaining. 

WET  ASSAYS  and  methods  of  detection.  Sulphide  of  hy- 
drogen and  sulphide  of  ammonium  throw  down  lead  as  black 
sulphide,  insoluble  in  any  amount  of  these  sulphide  preci- 
pitants. 

Potash  or  ammonia  throws  down  hydrated  oxide  soluble 
in  excess  of  potash,  but  not  of  ammonia. 

Alkaline  carbonates  precipitate  a  white  lead  carbonate 
which  is  quickly  blackened  by  sulphide  of  hydrogen. 

Sulphuric  acid  precipitates  a  white  sulphate ;   this  is  a 


204  MINERALS,   MINES,   AND   MINING. 

characteristic  test.  It  is  thrown  down,  also,  by  any  soluble 
sulphate. 

Potassic  chromate  is  the  most  delicate  test,  precipitating  a 
fine  yellow  lead  chromate  in  even  exceedingly  dilute  solu- 
tions. 

Hydrochloric  acid,  or  a  chloride  gives  a  white  precipitate 
soluble  in  excess  of  potash. 

When  lead  is  to  be  determined  quantitatively  it  is  usually 
precipitated  as  sulphate,  washed,  dried,  and  ignited  in  a  porce- 
lain crucible  before  weighing,  the  crucible  being  covered,  as 
"  the  sulphate  is  slightly  volatile."  (Makins.)  In  this  method 
the  solution  of  the  lead  salt  should  be  tolerably  concentrated, 
but  the  sulphuric  acid  diluted.  This  method,  however,  is 
not  so  accurate  as  adding  twice  the  bulk  of  alcohol  and 
giving  time  for  the  precipitate,  then  washing  the  latter  with 
alcohol;  it  should  then  be  dried,  ignited,  and  weighed.  Of 
this  68.32  per  cent,  is  lead. 

The  analysis  of  silver  lead  requires  a  solution  in  nitric 
acid.  Then  largely  dilute  and  add  a  large  excess  of  hydro- 
chloric acid  to  throw  down  the  silver.  The  lead  chloride  is 
prevented  from  going  down  by  this  dilution  and  excess  of 
acid. 

The  Galena  assay  (wet)  we  have  already  given. 

We  present  Mascazzinie's  method  of  assaying  lead  ore,  viz : 
The  ore  or  other  substance  is  oxidized,  and  its  metals  con- 
verted into  sulphates  before  reduction,  the  best  agent  for 
this  purpose  being  sulphate  of  ammonia.  The  ore  is  mixed 
with  an  equal  or  double  weight  of  sulphate  of  ammonia,  ac- 


LEAD.  205 

cording  as  it  is  supposed  to  be  poorer  or  richer,  and  the 
mixture  is  ignited  in  a  small  crucible  of  porcelain,  covered  to 
prevent  loss  from  spurting.  The  mass,  when  cold,  is  treated 
with  boiling  water,  acidulated  with  sulphuric  acid  arid  muriatic 
acid.  By  this  means  the  sulphates  and  oxides  of  iron,  copper, 
etc.,  are  dissolved,  while  lead  and  silver  remain  insoluble. 
This  portion  is  washed  by  decantation,  the  washings  being 
passed  through  a  filter.  This  filter  is  next  dried,  and  its 
ashes  are  added  to  the  dried  insoluble  portion.  It  is  then 
mixed  with  muriatic  acid  and  powdered  zinc,  in  order  to 
reduce  the  sulphate  of  lead  and  chloride  of  silver.  The 
metallic  deposit  is  washed  with  water  which  has  been  boiled, 
or  acidulated  with  sulphuric  acid,  and  is  then  pressed  into  a 
compact  mass.  This  is  dried  and  heated  with  from  1|  to  2 
parts  its  own  weight  of  a  flux  composed  of  13  grammes  car- 
bonate of  potassa,  10  grammes  carbonate  of  soda,  5  grammes 
of  melted  borax,  and  5  grammes  of  farina.  The  whole  is 
covered  over  with  dried  chloride  of  sodium,  and  heat  is  raised 
by  degrees  to  redness.  When  the  whole  is  in  a  state  of  quiet 
fusion,  it  is  submitted  for  a  moment  to  a  higher  temperature. 
This  process  serves  for  determining  lead  and  silver  in  white 
lead,  red  lead,  ores  rich  in  gold  and  silver,  also  antimony, 
tin,  and  copper.  If,  in  the  assay  of  ores  of  gold  and  silver, 
the  amount  of  lead  is  insufficient,  pure  oxide  of  lead  (litharge) 
is  added. 


206  MINERALS,   MINES,    AND   MINING. 


MANGANESE. 

Manganese  (symbol  Mn)  resembles  iron  in  several  par- 
ticulars, physical  and  chemical,  and  it  occurs  with  iron 
compounds.  The  metal  itself  has  not  yet  been  applied  to 
any  useful  purpose.  Metallic  manganese  may  be  obtained 
by  reducing  carbonate  of  manganese  with  charcoal  at  a  very 
high  temperature,  and  the  fused  mass  which  is  combined 
with  a  little  carbon  (as  in  cast  iron)  is  freed  from  its  carbon 
by  a  second  fusion  in  contact  with  carbonate  of  manganese. 
Metallic  Mn  is  darker  in  color  than  (wrought)  iron  and 
much  harder,  brittle,  and  feebly  attracted  by  the  magnet. 
Spec.  grav.  8.013;  its  geological  occurrence  is  said  to  be,  in 
one  mine,  upon  the  Silurian  limestone.  It  is  somewhat 
more  easily  oxidized  than  iron. 

WITH  THE  BLOWPIPE  a  compound  containing  Mn,  in 
however  small  a  quantity,  is  fused  on  a  piece  of  platinum 
foil  with  carbonate  of  soda,  a  mass  of  manganate  of  soda 
(Na2MnO4)  is  formed,  which  is  green  while  hot,  and  becomes 
blue  on  cooling.  The  oxygen  required  to  convert  the  lower 
oxides  of  manganese  into  manganic  acid  has  been  absorbed 
from  the  air.  (Bloxam.)  In  executing  this  test  turn  up 
the  edges  of  the  platinum  foil  and  apply  the  flame  of  the 
blowpipe  to  the  under  side  of  the  foil. 

ASSOCIATIONS.  It  is  sometimes  associated  with  some  sil- 
ver, though  the  oxide  of  Mn  remains  very  high  in  proportion, 
as  in  Montana.  At  the  Nile  mine  (Butte  ores),  the  Mn  de-  , 


MANGANESE.  207 

creases  as  the  silver  increases  in  the  ore.  It  sometimes 
contains  cobalt,  nickel,  and  rarely  zinc.  But  the  chief 
association  is  with  iron,  and  its  importance  is  very  largely 
due  to  the  influence  which  it  exerts  upon  metallic  iron  and 
steel. 

ITS  USES  in  the  arts  and  manufactures  are  found  in  the 
oxidizing  power  of  its  richest  ores,  which  are  manganese 
dioxides,  mineralogical  name  pyrolusite,  MnO3 ;  braunite  or 
the  brown  oxide,  Mn2O3;  manganife,  Mn2O3H2O;  hausma- 
nite,  Mn3O4 ;  and  psilomelane,  of  which  the  true  nature  is 
doubtful,  although  it  is  a  common  ore  of  manganese  in 
foreign  countries  and  contains  as  much  as  85  per  cent,  of 
manganic  oxides.  There  is  also  a  bog  manganese  called 
wad  which  has  been  found  in  New  York,  Maine,  Missouri, 
and  South  Carolina  and  other  States.  The  most  important 
mines  are  the  Crimora  mine  at  Crimora  Station,  on  the 
Shenandoah  Valley  Railroad,  Augusta  County,  Virginia ; 
one  in  Barton  County,  Georgia ;  Woodstock  Station,  Cal- 
houn  County,  Alabama;  and  more  recently  in  Arkansas 
and  in  California  and  Nevada. 

Manganese  oxides  are  used  for  the  purpose  of  furnishing 
oxygen,  and  for  the  production  of  chlorine  for  bleaching 
purposes  and  for  forming  bleaching  powders.  Large 
amounts  are  used  for  these  purposes.  It  is  said  that  one- 
fifth  of  the  manganese  ore  mined  in  the  United  States  is 
used  at  Pomeroy  and  at  other  places  on  the  Ohio  Eiver, 
in  the  West  Virginia  and  Ohio  salt  district,  for  making 
bromine.  It  is  also  used  in  glass. 


208  MINERALS,    MINES,   AND   MINING. 

Large  amounts  of  manganese  were  formerly  imported  to 
furnish  manganese  to  the  Bessemer  steel  works. 

But  other  very  important  ores  are  those  in  which  man- 
ganese forms  only  a  small  proportion,  but  yet  an  essential 
part.  These  are  the  iron  ores  containing  generally  about 
two  to  three  per  cent,  of  manganese,  for  the  irons  made 
from  these  ores  contain  that  amount  of  manganese  which 
seems  to  exert  a  purifying  power  over  the  steel  made  there- 
from which  could  not  otherwise  be  obtained. 

If  pure  manganese  could  readily  be  obtained,  that  would 
be  used.  But  this  cannot  be  had,  and  therefore  a  mixture 
of  the  oxides  of  manganese  and  of  iron  is  made  called 
"  spiegel"  iron  when  the  manganese  is  less  than  1 5  or  20 
per  cent.,  and  "  ferromanganese"  when  it  exceeds  this 
percentage. 

The  ores  for  this  purpose  should  be  highly  charged  with 
iron  so  as  to  obtain  as  high  an  amount  of  the  manganese  as 
possible,  as  this  condition  is  favorable  for  the  making  of  the 
alloy  of  the  manganese  and  iron ;  otherwise  the  manganese 
inclines  to  leave  the  iron  for  the  slag.  The  best  ores,  there- 
fore, are  those  which  contain  a  very  large  proportion  of  iron. 

As  a  matter  of  some  importance,  but  aside  from  that  just 
mentioned,  it  is  important  for  the  purposes  of  building  that 
the  mineralogist  should  determine  the  presence  of  the  oxide 
of  manganese  in  building  stones,  especially  the  sandstones 
of  cream-colored  shade,  brown,  or  gray.  Wherever  parti- 
cles of  manganese  oxide  exist  they  are  determinable  by  the 
blowpipe  and  the  borax  bead,  as  we  have  already  shown, 
and  their  presence  will  always  be  followed  by  disagreeable 


PLATINUM.  209 

streaks  of  dark  peroxide  running  down  the  side  of  the  stone 
and  disfiguring  the  building  and  its  ornaments  wherever  that 
stone  is  used.  Such  blocks  should  be  either  refused  alto- 
gether or  placed  where  dark  streaks  will  not  be  seen,  for 
although  very  small  specks  in  the  quarry,  when  placed  in 
the  outer  walls  they  invariably  increase  in  size  and  length 
after  every  rain  and  never  fade  away. 

The  analyses  for  manganese  by  the  WET  PROCESS  may  be 
found  treated  upon  in  connection  with  iron  in  the  article  on 
Iron.  Detection  of  minute  traces  of  manganese  may  be 
made  by  the  following  process :  Dissolve  the  compound  in 
a  little  nitric  acid ;  then  add  dioxide  of  lead  and  boil  the 
mixture,  when  the  least  trace  of  manganese  will  produce  a 
red  tint  of  permanganic  acid. 


PLATINUM. 

Found  NATIVE,  but  combined  with  gold,  iron,  iridium, 
rhodium,  palladium,  copper,  osmium,  and  chromite  (Dana), 
and  ruthenium  and  occasionally  lead  and  manganese. 
(Makins.)  Ir,  Ru,  Rh,  Os,  Pd,  are  the  platinum  metals. 

HARDNESS,  4  to  4.5;  GRAY.,  16  to  19;  LUSTRE,  metallic; 
COLOR  and  streak,  whitish  steel-gray. 

It"  has  been  supposed  to  be  slightly  magnetic,  but  this 
seems  due  entirely  to  the  iron  contained  in  the  magnetic 
specimens.  It  is  found  in  fine  grains  and  masses  as  heavy 
as  11.57  pounds  troy,  and  one,  the  largest  yet  reported, 
weighing  21  pounds  troy,  in  the  DemidofF  cabinet. 

14 


910  MINERALS,   MINES,    AND   MINING. 

GEOLOGY  AND  OCCURRENCE.  It  is  found  in  alluvial  dis- 
tricts, but  wherever  this  is  the  case  it  seems  to  owe  its  pres- 
ence there  to  transportation  from  the  earliest  rocks.  In 
Russia  it  is  found  with  chrome-iron  ore  in  serpentine.  About 
80  per  cent,  of  the  world's  platinum  comes  from  this  source 
and  about  15  per  cent,  from  the  gold  washings  of  the  Pinto, 
province  of  Antioquia,  at  the  headwaters  of  the  Atral 
River,  in  the  United  States  of  Colombia.  In  Brazil  it  is 
associated  with  syenite.  It  has  been  noticed  lately  in  a 
quartz  vein  impregnated  with  gold-bearing  iron  pyrites  in 
the  Thames  gold  district,  New  Zealand.  Here  it  seems  to 
have  been  in  place. 

In  the  United  States  it  has  been  found  in  small  quantities 
associated  with  placer  gold,  and  in  some  places  of  the  Pacific 
slope  only  has  it  been  found  in  merchantable  quantities.  It 
occurs  in  California  at  Hay  Fork,  a  branch  of  the  Trinity 
River,  on  the  North  Fork,  in  Butte  County ;  in  the  hydraulic 
mines  around  Cherokee  and  Oroville,  occasionally  for  nine 
parts  of  gold  found  here  one  part  is  platinum.  Also  found  in 
Mendocino  County,  in  Anderson  Valley,  Novarro  River,  and 
other  places.  Also  on  the  beach  between  Capes  Blanco  and 
Mendocino,  on  the  Merced  and  Tuolumne  rivers  in  that  State. 
Going  farther  north  the  amount  of  platinum  increases.  On 
the  Oregon  coast  the  proportion  of  gold  to  platinum  in  the 
placers  is  sometimes  five  to  one,  and  in  rare  instances  the 
amount  of  platinum  equals  the  gold.  Platinum  has  been 
reported  as  occurring  in  Idaho  and  in  the  Black  Canon  and 
on  the  Agua  Fria,  in  Arizona,  though  the  occurrence  in  the 
latter  Territory  is  not  well  authenticated.  Also  a  consider- 


PLATINUM.  211 

able  quantity  was  brought  by  a  private  individual  in  grains 
and  small  pieces  to  Philadelphia  for  examination,  which  was 
said  to  have  been  gathered  by  him  on  the  Yellowstone 
River. 

California  ore  sometimes  yields  the  refiner  only  fifty  per 
cent,  of  its  weight  in  pure  platinum.  The  following  analy- 
sis of  California  ore  will  give  some  idea  of  its  associations: — 

Per  cent. 
Platinum 85.50 

Gold  ,,:,*,-.:,  '-.;„'  ':%'-•;.  'f;  ..v  _.,;.,  *!^  .80 
Iron  .  .,;.-..>  ;•  •  •  .  V  ....  6.75 
Iridium  .  .  / .  .  ..  .*  /.  .  1.05 
Rhodium  .  *  |'il  •  *  '.  .  -  J  •*•  1-00 
Palladium  ^  ;?  5  "•:;*.'  ; '  -**  .  .-,,<'  •<>,.'  *\  <.> .  -60 
Copper  ^,  .  v~  .  .  >  .  ,  .  v  1.40 
Osmiridium  ..  .  .  -v»"-  .  '  *  .  1.10 
Sand  2.95 


101.15 

The  osmiridium  (iridosmine)  is  an  alloy  of  osmium  and 
iridium,  which  is  separated  by  its  insolubility  in  nitro-hydro- 
chloric  acid.  The  sand  mentioned  contains  quartz,  chrome- 
iron  ore,  hyacinth,  spinel,  and  titanic  iron.  (Williams.) 

The  production  of  platinum  in  the  United  States  during 
1883  is  estimated  at  200  troy  ounces  and  in  1884  at  150 
troy  ounces.  The  use  of  platinum  in  electric  lights  (incan- 
descent) has  largely  increased  the  demand. 

When  the  proportion  of  iridium  reaches  twenty  per  cent. 
the  alloy  is  scarcely  attacked  by  mtro-hydrochloric  acid. 

THE  WET  PROCESS  of  analysis.  As  the  platinum  metals  are 
soluble  only  in  nitro-hydrochloric  acid,  the  ore  may  be  puri- 
fied in  part  by  employing  the  components  of  this  acid  sue- 


UNIVERSITY 


212  MINERALS,   MINES,    AND    MINING. 

cessively.  It  is,  therefore,  first  heated  with  nitric  acid  ;  thus 
any  copper,  lead,  iron,  and  silver  are  dissolved.  Then,  after 
washing,  a  second  such  operation  with  hydrochloric  acid 
will  remove  any  magnetic  iron  ore  left  in  it.  The  ore  is 
now  in  a  fit  state  to  be  treated  with  nitro-hydrochloric  acid, 
made  from  pure  nitric  and  hydrochloric  acids.  But,  in  order 
to  prevent  the  solution  of  one  of  the  metals,  iridium,  it  is 
diluted  for  use  with  an  equal  bulk  of  water.  The  propor- 
tions Wollaston  advises  are,  to  100  parts  of  ore  as  much  hy- 
drochloric acid  as  contains  150  parts  of  actual  (dry)  acid, 
mixed  with  nitric  equal  to  40  parts  (by  weight)  of  dry,  i.  e., 
free  from  water.  Solution  will  be  complete  after  three  or 
four  days'  digestion,  but  towards  the  end  it  is  always  neces- 
sary to  assist  this  by  gentle  heat.  The  vessel  is  then  set 
aside,  in  order  that  suspended  matter,  which  is  almost  en- 
tirely iridium,  may  be  deposited.  The  clear  solution  is  then 
syphoned  off,  and  to  it  ammoniac  chloride,  amounting  to  41 
parts  (volume),  is  added.  This  throws  down  a  yellow  crys- 
talline precipitate,  which  is  ammonio-platinic  chloride ;  this 
on  heating  will  be  decomposed  and  yield  platinum.  By 
this  first  precipitation  about  65  parts  of  platinum  are  at  once 
separated  from  the  ore,  the  weight  of  the  compound  salt 
being,  in  this  case,  about  165  parts.  About  11  parts  of 
platinum  are  left  in  the  mother  liquor  of  the  crystals,  associ- 
ated with  nearly  the  whole  of  the  other  metals.  A  clean 
plate  of  zinc  is  then  put  into  it  which  will  precipitate  them 
all.  This  deposit  is  first  washed  clean,  and  then  redissolved 
in  aqua  regia ;  and  to  the  solution  one-thirty-second  of  its 
bulk  of  strong  hydrochloric  acid  is  added,  after  which  more 


PLATINUM.  213 

ammoniac  chloride,  so  as  to  throw  down  the  remainder  of 
the  platinum.  This  addition  of  hydrochloric  acid  last  made 
is  for  the  prevention  of  the  precipitation  of  any  palladium, 
or  lead,  with  it.  But  the  palladium  may  be  separated  at 
the  first,  by  first  neutralizing  the  solution  with  sodic  carbon- 
ate, and  then  adding  mercuric  cyanide ;  this  throws  down 
the  palladium,  after  removing  which  the  addition  of  ammo- 
niac chloride  will  precipitate  the  platinum. 

As  the  solution  of  the  ore  in  aqua  regia  takes  place  very 
slowly,  it  has  been  advised,  in  place  of  mixing  and  adding 
the  acids  at  once,  to  put  the  hydrochloric  on  the  ore,  and 
then  add  the  nitric  by  degrees,  as  solution  progresses ;  and 
no  doubt  acid  may  be  thus  economized. 

The  precipitates  of  ammonio-platinic  chloride  are  always 
contaminated  with  iridium,  a  portion  of  which  has  formed  a 
soluble  double  salt  with  ammoniac  chloride ;  therefore  they 
are  carefully  washed  with  cold  water,  which  will  partially 
remove  this,  and  afterwards  pressed  slightly  between  layers 
of  filter  material  and  then  dried. 

It  now  only  remains  to  ignite,  in  order  to  separate  the 
ammonia  salt ;  this  requires  much  care  so  as  not  to  use  heat 
enough  to  agglutinate  the  reduced  metal,  the  success  of  the 
after  working  of  which  mainly  depends  upon  its  fine  divi- 
sion. 

For  this  reduction  it  is  put  into  a  black  lead  crucible  and 
heated  until  only  the  platinum,  in  fine  powder,  is  left.  This 
is  removed,  any  lumps  broken  up,  and  then  rubbed  to  pow- 
der with  a  wooden  mortar  and  pestle,  the  rubbing  being 
light  so  as  not  to  burnish  or  condense  the  powder  in  the 


214  MINERALS,   MINES,    AND   MINING. 

least.  This  powder  is  the  platinum,  and  the  next  move- 
ment is  to  consolidate  this  mass  without  melting  because  of 
the  exceeding  heat  required.  But  in  the  analysis  this  is 
not  necessary,  since  it  may  be  filtered  out,  dried,  and  weighed. 
This  process,  however,  does  not  entirely  eliminate  the 
indium  from  the  platinum,  but  while  in  the  arts  this  is  no 
objection,  but  renders  the  platinum  less  liable  to  be  affected 
by  chemicals,  and  harder  and  less  easy  to  melt,  yet  in  analy- 
sis the  platinum  may  be  needed  separate  as  in  completion  of 
the  constituents,  hence  the  separation  is  called  for  and  ef- 
fected thus :  The  solution  of  the  two  metals  is  treated  with 
potassic  chloride ;  the  precipitate  is  fused  after  washing  with 
twice  its  weight  of  potassic  carbonate.  Thus  the  iridium  is 
oxidized,  while  the  platinum  is  reduced  to  the  metallic  con- 
dition. By  boiling  the  whole  in  water  all  potash  salts  are 
removed,  and  then,  on  treating  the  residue  with  nitro-hydro- 
chloric  acid,  the  platinum  is  dissolved,  leaving  the  insoluble 
iridium  oxide  untouched  by  it.  If  any  iridium  is  yet  found 
in  the  product,  this  operation  may  be  repeated.  Potassic 
cyanide  solution  may  also  be  used  for  the  separation,  for,  on 
digesting  the  precipitate  in  it,  the  iridium  salt  will  dissolve 
while  the  platinum  ore  is  insoluble. 


IRIDIUM. 

This  metal  does  not  occur  unalloyed.  It  is  associated 
with  osmium  in  different  proportions,  and  in  this  sense  it 
may  be  said  to  occur  NATIVE.  Mineralogical  name  Iridos- 
mine.  HARDNESS  6  to  7;  GRAY.  19.3  to  21.12.  (Dana.) 


IRIDIUM. 


215 


LUSTRE  metallic,  and  COLOR  tin-white  and  light  steel-gray. 
Opaque.  Malleable  with  difficulty. 

Its  name  is  derived  from  the  various  colors  of  its  com- 
pounds, which  are  green,  blue,  and  yellow.  The  protoxide, 
IrO,  in  solution  in  potash  becomes  blue  when  exposed  to  air, 
from  the  formation  of  the  binoxide,  IrO2.  The  teroxide  is 
green.  Iridium  resembles  palladium  in  its  disposition  to 
unite  with  carbon  when  heated  in  the  flame  of  a  spirit-lamp. 

The  following  table  exhibits  a  general  view  of  the  analy- 
tical process  by  which  the  remarkable  metals  associated  in 
the  ores  of  platinum  may  be  separated  from  each  other, 
omitting  the  minor  details  which  are  requisite  to  insure  the 

purity  of  each  metal.     (Bloxam.) 

jti-.-  - 

Analysis  of  the  ore  of  Platinum.     Boil  with  aqua  regia. 


Dissolved: 

PLATINUM,  PALLADIUM,  RHODIUM. 
Add  chloride  of  ammonium. 


Undissolved : 

IRIDIUM,  OSMIUM,  RUTHENIUM. 

Chrome  iron,  Titanic  iron,  etc. 

Heat  in  current  of  dry  air. 


Precipitated  : 

Solution: 

Volatilized 

Carried 

Residue  : 

PLATINUM 

Neutralize  with  carbo- 

OSMIUM. 

forward  by 

Mix  with  chloride  of 

nate  of  soda  ; 

as 

as  Os04. 

the  current: 

sodium,  and  heat  in 

add  cyanide  of  mercury. 

2NH4Cl,PtCl4. 

RUTHENIUM 

current  of  chlorine. 

as  Ru02. 

Treat  with  boiling  water. 

Precipitated  : 

Solution  : 

PALLADIUM 

Evaporate 

as  PdCy2. 

with  hydro- 

Dissolved: 

Residue  : 

chloric  acid. 

IRIDIUM  as 

Titanic  iron, 

Treat  with 

2NaCl.IrCl4. 

Chrome  iron, 

alcohol. 

etc. 

Insoluble 

RHODIUM  as 

3NaCl.RoCl3. 

216  MINERALS,    MINES,   AND   MINING. 

Neither  rhodium   nor  iridium  is   attacked    by  nitre-hydro- 
chloric acid,  unless  alloyed  with  platinum. 

The  geographical  distribution  of  this  metal  is  quite  wide ; 
it  is  found  in  foreign  countries,  in  Russia,  East  India,  Borneo, 
South  America,  Canada,  Australia,  France,  Germany,  and 
Spain.  The  principal  source  is  in  the  Ural  Mountains,  in 
Russia,  associated  with  platinum  and  gold,  and  the  associa- 
tion in  chief  is  with  platinum  and  osmium,  as  platiniridium 
and  osmiridium,  in  the  former  of  which  the  iridium  amounts 
to  76.80  per  cent,  and  the  platinum  to  19.64,  in  the  osmi- 
ridium the  iridium  is  55.24  per  cent.,  the  platinum  10.08, 
while  the  osmium  is  27.32  for  the  Ural  specimens. 

In  the  United  States,  this  metal  is  found  in  California  and 
Oregon,  and  in  Williams's  report  it  is  stated  as  found  quite 
abundantly  in  the  river  sands  of  the  northern  counties  of 
the  former  State.  Considerable  quantities  accumulate  in  the 
mints  and  assay  offices,  obtained  from  the  crucibles  in  melt- 
ing placer  gold. 

Iridium  ore  is  a  source  of  great  annoyance  when  mixed 
with  gold  dust  on  account  of  its  specific  gravity,  which  is 
about  19.3,  being  nearly  the  same  as  that  of  gold.  Conse- 
quently, it  is  impossible  to  separate  the  gold  from  the  iridium 
by  the  process  of  washing,  but  as  neither  iridium  nor  its  ores 
combine  with  mercury,  the  gold  may  be  amalgamated  and 
the  iridium  remain  behind.  Or  the  gold  may  be  separated 
by  solution  in  aqua  regia,  which  has  no  effect  upon  iridium. 

In  the  mints  these  metals  are  frequently  separated  in  the 
crucible  by  allowing  the  melted  gold  to  stand  for  some  time 
when  the  iridium  settles  and  the  gold  may  be  poured  off. 


IRIDIUM.  217 

The  gold  in  the  dregs  is  dissolved  and  the  iridium  remains. 
In  the  San  Francisco  mint  150  to  300  ounces  of  iridosmine 
are  accumulated  annually. 

It  is  supposed  that  the  iridium  which  was  claimed  to  have 
been  melted  by  the  older  chemists  was  alloyed,  since  the 
iridium  of  the  present  day  is  not  of  the  same  nature  "  duc- 
tile" and  18.68  for  gravity  as  then  reported,  but  extremely 
hard  and  22.38  in  gravity. 

The  important  discovery  of  Mr.  John  Holland,  of  Cincin- 
nati, Ohio,  that  a  combination  of  phosphorus  and  iridium 
could  be  made  by  heating  the  latter  to  a  white  heat  and 
adding  the  former,  has  made  it  possible  to  melt  iridium  in  a 
crucible  and  pour  the  iridium  into  ingots.  This  iridium, 
which  contains  about  7J  per  cent,  of  phosphorus,  has  the 
physical  properties  of  the  iridium  without  the  phosphorus, 
so  far  as  hardness  is  concerned,  and  can  be  remelted  at  a 
white  heat.  But  in  its  fusibility  it  cannot  be  used  for  some 
purposes  before  the  phosphorus  is  removed.  This  is  done  by 
heating  the  phosphorus-iridium  in  a  lime  crucible  within  an 
electric  current.  By  this  means  the  phosphorus  is  entirely 
removed. 

The  natural  grains  of  iridosmine  are  used  for  pointing 
gold  pens.  These  are  soldered  on  the  points  and  cut  down 
to  shape  by  diamond,  or  corundum,  dust,  upon  the  edge  of 
a  copper  wheel  rotating  about  3000  revolutions  per  minute. 

Many  other  uses  are  now  being  made  of  this  metal,  all 
dependent  upon  the  facts  of  its  exceeding  hardness  and  its 
infusibility ;  its  melting- point  as  pure  iridium  has  been 


218  MINERALS,   MINES,   AND   MINING. 

estimated  (Violle),  at  1950°  C.  and  platinum  at  1750°  C., 
or  3542  F.  and  3182  F.  respectively. 

Iridosmine  as  it  comes  from  the  mines,  having  been 
thoroughly  washed  and  free  from  "  black  sand,"  is  worth 
from  $2  to  $5  per  ounce,  pure  iridium  being  worth  about 
$20  per  ounce.  Selected  grains  of  iridosmine  suitable  for 
pen  points  have  a  market  value  of  from  $50  to  $75  per  ounce. 
(Wm.  L.  Dudley.) 


MERCURY. 

OCCURRENT  FORMS:  NATIVE,  in  small  globules  scattered 
through  its  gangue ;  also  in  quartz  geodes  containing  several 
pounds  of  mercury,  at  the  Prince's  Mine  in  the  Napa  Valley, 
California.  (Dana.)  Also  associated  with  some  of  its  ores, 
cinnabar  especially.  (Miller.) 

HARDNESS  :  liquid  in  a  temperature  higher  than — 39°  Fah. ; 
becomes  solid  at  temperature  under — 40°F.  ==  39.44°. 
(Bristow.) 

GRAVITY:  13.568.  (Bristow.)  When  solid  15.6,  with 
octahedral  crystallization. 

COLOR:  tin  white. 

DUCTILITY:  in  liquid  form  elastic;  as  a  solid,  malleable 
and  ductile,  but  not  in  a  high  degree. 

COMPOSITION:  mercury,  with  sometimes  a  little  silver,  and 
sometimes  gold.  (Crookes  and  Rohrig.) 

IT  BOILS  at  660°  F  =  349.5°  C.,  but  evaporates  at  ordinary 
temperature. 


MERCURY.  219 

LOCALITIES  :  chiefly  at  Almaden,  a  town  of  La  Mancha, 
in  Spain ;  and  Idria,  in  Carniola ;  in  Wolfstein,  in  Rhenish 
Bavaria ;  in  Hungary,  France,  Peru,  and  California ;  small 
quantities  of  native  metal  are  found  in  various  other  places. 

GEOLOGY  AND  ASSOCIATIONS  :  the  rocks  affording  the  metal 
and  its  ores  are  mostly  clay  shales,  or  schists  of  different 
geological  ages.  (Dana.)  At  Cividale,  in  Venetian  Lom- 
bardy,  it  is  found  in  a  marl  regarded  as  a  part  of  the  Eocene 
nummulitic  beds — occasionally  found  in  the  drift;  springs 
sometimes  bear  along  globules  of  mercury,  as  from  the  Car- 
pathian sandstone  of  Transylvania  and  Gallicia.  At  Mount 
Idria  it  occurs  interspersed  through  a  clay  slate.  (Dana.)  At 
Almaden  the  mercury  is  said  not  to  form  veins,  but  to  have 
impregnated  the  vertical  strata  of  quartzose  sandstone  asso- 
ciated with  carbonaceous  slates;  and  in  the  Asturias  the 
mines  are  worked  in  coal  strata.  (David  Page.)  The  strata 
in  which  the  Almaden  mines  occur  belong  to  the  upper  Silu- 
rian; the  immediate  wall-rock  is  usually  a  black  carbonace- 
ous slate  and  quartzite,  with  which  hard,  fine-grained,  sand- 
stones and  slates  alternate,  but  contain  no  ores.  The  deposits 
decline,  at  the  surface  60°  to  70°,  then  dip  almost  vertically. 
They  had  been  opened  in  1851  to  a  depth  of  1050  feet,  and 
they  strike  E.  to  W.  Sometimes  in  this  mine  the  ore  is 
associated  with  iron-pyrites  and  ophite  (a  tolerably  compact 
diorite).  (Cotta  by  Prime.)  Ores  of  mercury  are  found  in 
the  eastern  portion  of  the  Saarbriick  coal-basin,  in  lodes,  and  as 
impregnations ;  in  the  rocks  of  the  carboniferous  formation,  in 
porphyry  and  amygdaloid.  According  to  Von  Dechen,  the 
lodes  of  the  Potz  Mountain  are  in  the  strata  of  the  carboni- 


220  MINERALS,   MINES,   AND    MINING. 

ferous  formation,  and  such  igneous  rocks  as  traverse  them. 
"  The  general  character  of  these  quicksilver  lodes  and  the 
fact  that  the  ores  are  almost  only  found  at  a  moderate  depth, 
distributed  in  the  numerous  fissures  of  the  rock,  would  seem 
to  prove,  that  most  of  the  ores,  especially  those  of  mercury, 
have  penetrated  into  the  fissures  by  a  process  of  sublimation, 
and  that  a  tolerably  extended  district  was  subjected  for  a 
considerable  period  to  these  sublimations,  in  such  a  manner 
that  the  same  penetrated  wherever  a  possibility  existed  for 
their  doing  so,  and  were  deposited  at  a  certain  level  (by  a 
certain  temperature),  having  some  choice  as  to  the  rocks 
which  they  selected."  (Cotta  by  Prime.) 

CHEMICAL  CHARACTERISTICS.  Mercury  is  readily  dissolved 
by  nitric  acid,  and  the  nitrate  is  formed  with  evolution  of 
nitric  oxide;  if  the  nitric  acid  is  dilute,  the  action  is  slow 
and  crystals  are  formed  of  mercurous  nitrate. 

Sulphuric  acid  dissolves  it  with  heat,  forming  a  sulphate, 
and  at  the  same  time  sulphurous  acid  is  evolved.  Hydro- 
chloric acid  has  no  action  upon  it.  It  combines  directly  at 
ordinary  temperatures  with  chlorine,  iodine,  and  bromine,  and 
it  combines  readily  with  gold,  silver,  tin,  lead,  bismuth,  cad- 
mium and  zinc,  with  some  more  difficulty  with  copper  and 
iron.  When  potassium  or  sodium  is  associated  with  it,  it 
readily  adheres  even  to  steel. 

Two  oxides  of  mercury  are  known,  the  suboxide  Hg2O, 
and  the  oxide  HgO.  The  suboxide  is  called  the  black  oxide, 
or  mercurous  oxide  ;  the  oxide  is  called  the  red  oxide,  or  red 
precipitate,  becomes  nearly  black  when  heated  and  is  resolved 
into  mercury  and  oxygen  at  a  red  heat.  A  bright  yellow 


MERCURY.  221 

modification  of  the  oxide  is  precipitated  when  a  solution  of 
corrosive  sublimate  (HgCl2)  is  decomposed  by  potash.  The 
yellow  variety  is  chemically  more  active  than  the  red. 

ORES.  The  New  Almaden  Mine,  in  California,  is  the  most 
important  in  the  United  States,  and  supposed  to  be  second, 
in  product,  in  the  world,  Almaden,  in  Spain,  being  first. 
The  ore  is  cinnabar,  which  is  a  native  sulphide,  varying  in 
color  from  dark  brown  to  red,  SPEC.  GRAVITY  8.2;  streak  red. 
Neither  hydrochloric  nor  nitric  acid  will  effect  a  solution,  but 
a  mixture  of  the  two  dissolves  it,  forming  mercuric  chloride 
with  separation  of  sulphur.  Pyrite,  occasionally,  accom- 
panies the  ore,  bitumen  is  quite  common  and  is  intimately 
associated  with  the  cinnabar.  Some  native  mercury  is  also 
present. 

The  ore  is  first  broken  and  passed  through  bar-screens 
placed  about  one  inch,  or  inch  and  a  quarter  apart,  and  the 
sizes  of  ore  passed  through  in  this  condition  are  called  tierras 
(or  fine  ore).  The  large  pieces  which  do  not  pass  through 
are  picked  over  and  that  which  contains  cinnabar  is  reduced 
to  less  than  9  inches,  and  these  in  the  quantity  are  known 
as  granza,  or  coarse  ore.  But  these  sizes  and  sorts  are  again 
picked  over  at  the  reducing  furnaces,  changed  in  size  and 
richness.  At  the  mine  the  granza  is  often  associated  with 
serpentine,  and  as  a  whole  contains  only  from  6  to  8  per  cent, 
of  metallic  quicksilver.  The  waste  is  also  picked  and  any  sign 
of  cinnabar  causes  it  to  be  kept,  washed,  and  set  out  in  the 
weather,  and  it  is  called  terrero,  its  quicksilver  contents  being 
only  about  1  or  2  per  cent. 

The  granza  and  the  tierras  are  weighed ;  the  terrero  and 


222  MINERALS,   MINES,   AND   MINING. 

other  dump  material  are  estimated  by  volume,  the  latter 
weighing  about  85  pounds  to  a  cubic  foot  and  23.5  cubic  feet 
to  the  ton. 

The  method  of  treatment  is  adapted  to  the  nature  of  the 
above  classifications. 

In  former  times  the  retort  process  was  used,  necessitating 
crushing  all  the  ores  in  order  to  mix  them  with  lime,  but 
this  was  abandoned  some  years  ago,  because  of  the  salivation 
of  the  workmen  caused  by  vapors  and  dust  arising  from  and 
because  of  the  process.  Hence  attempts  were  made  to 
roast  the  ores  and  condense  the  quicksilver  arising  from  the 
combustion.  This  roasting  is  performed  only  in  case  of  the 
larger  poorer  masses  in  cylinder  furnaces  of  the  Rum  ford 
pattern,  vertically  kindled  with  fires  at  the  bottom  outside 
and  the  ores  arranged  so  that  they  do  not  intercept  the 
upper  draft  or  ascent  of  heat  to  too  great  an  extent.  This 
is  done  by  placing  heavy  larger  or  spent  pieces  at  the  bot- 
tom of  an  hexagonal  cylinder  of  sheet  iron  whose  upper 
half  is  cylindrical,  the  lower  half  only  being  hexagonal. 
The  lower  half  is  prepared  with  the  fireplaces  below,  out  of 
the  line  of  the  cylinder,  vertically,  and  the  draw-holes  below 
for  removing  the  ore  when  all  the  quicksilver  has  been 
roasted  out.  The  uppermost  part  is  covered  with  a  flat 
dome  at  the  top  with  an  arrangement  for  dumping  in  the 
ores  and  covering  quickly  to  avoid  the  loss  of  the  quicksilver 
in  vapor.  The  sides  near  the  top  are  provided  with  exit 
pipes  for  conveying  the  quicksilver  vapors  into  condensers. 
This  furnace  is  only  for  the  coarse  ores  which  cannot  be 
treated  in  the  Hiittner  &  Scott  shelf  furnace ;  this  we  shall 


MERCURY.  223 

describe.  After  many  experiments  and  improvements  the 
resultant  form  remained  as  follows:  The  ore  body  of  the 
furnace  consists  of  a  long  narrow  room  running  upward  to 
a  proportionably  high  elevation  and  with  openings  in  the 
end  walls,  "  pigeon-holes ;"  from  either  side  wall  of  this  ore 
chamber  project  tile  shelves  to  catch  the  small  ore  which  is 
thrown  in  from  the  top  of  the  furnace  or  ore  chamber. 
These  shelves  incline  inward  to  the  wall,  thus  catching  the 
falling  ore  and  throwing  it  back  against  the  wall.  The 
shelves  on  opposite  sides  are  not  opposite  each  other,  but 
alternate,  so  that  the  ore  is  more  likely  in  falling  to  be 
caught  as  it  falls  upon  and  strikes  one  shelf  by  the  other  shelf 
opposite,  and  the  distance  from  one  shelf  vertically  downward 
to  the  other  varies  as  the  fineness  of  the  ore  from  three  to 
eight  inches.  The  edges  of  these  shelves  lap  under  each  other, 
so  that  when  they  are  over  full  the  fine  ore  slides  off  and  is 
caught  by  the  lower  shelf  and  pitched  back  to  the  wall  until 
too  full,  when  it  begins  to  deliver  to  the  next  below,  and  so 
on,  till  the  furnace  is  fully  charged,  of  which  fact  the  workman 
must  judge  by  peep-holes  aided  by  his  experience  in  charg- 
ing. When  fine  ore  is  fed  into  the  ore  chamber  through 
the  hopper  at  the  top  it  runs  from  one  shelf  to  the  next  un- 
til the  column  finds  support  upon  the  discharge  apparatus 
at  the  bottom,  whereupon  the  whole  column  comes  to  rest 
throughout  the  structure.  Thus  the  shelves  of  the  ore 
chambers  are  kept  covered  by  an  irregular,  zigzag  column 
of  ore.  The  end  walls  of  the  chamber  are  pierced  with 
pigeon-holes  so  that  the  flames  may  pass  from  the  fireplace 
under  each  shelf  and  over  the  ore  lying  upon  the  shelf  be- 


224  MINERALS,   MINES,   AND   MINING. 

neath  to  a  vapor  chamber  on  the  opposite  end  of  the  ore 
chamber.  Thence  they  pass  to  the  condensers.  In  the  first 
experimental  form  the  flames  made  only  one  passage  across 
the  ore  chambers.  The  furnace  as  thus  constructed  roasted 
the  ores  well  enough,  but  the  escaping  vapors  were  still 
quite  hot  and  the  consumption  of  the  fuel  was  considerable. 
This  loss  of  heat  was  provided  for  by  arches  placed  across 
the  vapor  chambers  and  over  the  fire-box,  so  that  the  air  and 
fumes  were  compelled  to  make  four  passages  across  the  fur- 
nace on  their  way  to  the  condensers. 

*It  will  be  seen  that  this  method  is  superior  to  that  of 
working  the  fine  ore  into  bricks  with  clay  and  roasting,  for 
the  making  of  these  bricks,  called  "adobes,"  caused  an  out- 
lay of  work  and  expense  of  about  ninety-five  cents  to  the 
ton  of  ore  which  is  now  entirely  unnecessary  in  the  shelf 
furnace. 

In  the  old  intermittent  furnaces,  only  one  of  which  is 
now  used  at  New  Almaden,  the  chamber  is  12  feet  long,  9 
feet  wide,  and  17  feet  6  inches  high,  inside  measures,  and 
the  charge  of  ore  is  80  to  100  tons,  arranged  with  graded  as- 
cent openings  in  the  ore  to  the  top,  with  channels  from  the 
fireplace  to  the  vapor  chamber  at  opposite  ends  of  the  fur- 
nace. The  graded  condition  is  called  for  by  the  natural 
tendency  of  hot  air  to  roast  the  upper  rather  than  the  lower 
layers  of  ore  ;  the  channels  are  made  smaller  and  further 
apart  in  the  upper  layers  of  ore,  and  a  certain  amount  of 
tierras  and  soot  from  the  condensers  is  added  to  the  coarse 
ore  for  the  same  reason.  But  the  intermittent  furnaces  are 
no  longer  used  to  treat  tierras,  and  the  model  of  the  old 


MERCURY.  225 

Rumford  limekiln  improved  upon  at  Idria,  Austria,  by  Ber- 
grath  Exeli,  and  in  some  respects  still  further  improved  upon 
for  coarse  ore  shaft  roasting  furnaces  with  exterior  firing,  is 
fully  explained  by  Samuel  B.  Christy  in  a  paper  read  before 
the  American  Institute  of  Mining  Engineers  and  found  also 
in  Williams's  "  Mineral  Resources"  in  U.  S.  Geological  Sur- 
vey, 1883  and  1884. 

Characteristics  of  mercurial  compounds. — If  a  substance 
supposed  to  contain  mercury  be  insoluble,  a  portion  of  it 
may  be  placed  in  a  hard  glass  tube  and  then  covered  with  a 
thick  layer  of  dry  sodic  carbonate  and  subsequently  heated. 
If  mercury  be  present,  it  will  separate  and  condense  in 
globules  in  a  cool  part  of  the  tube.  All  mercuric  com- 
pounds are  dissipated  by  heating  only.  If  the  suspected 
body  be  soluble,  a  solution  of  it  may  be  made  and  into  it  a 
strip  of  clean  copper  placed.  Mercury  will  be  reduced 
upon  it  which  may  be  polished  to  a  silvery  appearance,  and 
if  the  strip  be  afterwards  heated  in  a  glass  tube  the  mercury 
may  be  sublimed  off  the  copper. 

Stannous  chloride  added  may  at  once  throw  down  a  gray 
precipitate  of  metallic  mercury  ;  but  if  it  do  so,  the  compound 
contained  mercury  in  the  state  of  sub-oxide.  If,  on  the  other 
hand,  the  precipitate  appears  white  during  the  addition  of 
this  reagent,  and  before  sufficient  of  it  has  been  added,  the 
mercury  was  contained  as  protoxide.  The  first  white  pre- 
cipitation depended  upon  the  formation  of  calomel,  which 
latter  becomes  reduced  to  the  metallic  state  upon  the  com- 
plete addition  of  the  tin  salt. 

Potash,  soda,  or  ammonia  gives  a   black  precipitate  in 

15 


226  MINERALS,   MINES,   AND   MINING. 

salts  of  the  suboxide,  insoluble  in  any  excess,  but  if  potash 
gives  a  reddish  precipitate,  and  ammonia  a  white  one,  the 
mercury  was  in  form  of  a  protoxide. 

Hydrochloric  acid  gives  no  precipitate  in  salts  of  protoxide, 
but  throws  down  white  subchloride  in  salts  of  suboxide. 

If  to  the  unknown  solution,  sulphide  of  hydrogen,  or  am- 
monium sulphide  be  added  very  cautiously,  and  a  black  pre- 
cipitate appears  at  once,  it  is  due  to  a  suboxide ;  but  if  the 
precipitate  is  at  first  white,  then  brown,  and  at  last  black,  it 
is  from  the  presence  of  protoxide.  This  last,  if  removed  and 
heated,  will  sublime  as  a  dark-red  cinnabar  or  vermilion. 
The  sulphides  of  either  oxide  are  quite  insoluble  in  excess 
of  the  above  precipitants,  or  in  potassic  cyanide. 

An  accurate  method  (Makins)  for  determining  mercury 
in  compounds  is  the  following  one.  The  compound  is  heated 
with  dry  lime,  being  placed  in  a  combustion  tube  18  inches 
long,  having  at  one  end  a  receiver — generally  blown  in  the 
tube.  Into  this  tube  a  small  plug  of  asbestos  is  put  close  to 
the  receiver  end.  Then  dry  fragments  of  quicklime  are 
added  until  they  reach  nearly  to  the  centre  of  the  tube,  next 
the  mercurial  compound;  a  carefully  weighed  quantity  of 
about  20  grains  being  employed,  or  ranging  from  one  to  two 
grammes.  After  this  the  tube  is  fitted  to  its  front  end  with 
more  lime.  It  is  next  arranged  in  a  combustion  furnace. 
To  the  outer  end  of  the  tube  is  connected  a  small  tube  from 
an  apparatus  for  the  evolution  of  dry  hydrogen  gas ;  a  current 
of  the  latter  being  passed  in,  the  combustion  tube  is  heated 
to  redness  by  hot  charcoal,  commencing  at  the  end  next  the 
receiver,  and  carrying  it  back  to  the  outer  end.  After  the 


ANTIMONY.  227 

full  decomposition  of  the  specimen,  the  evolution  of  the  gas 
is  steadily  kept  up  till  all  watery  vapor  is  driven  out ;  after 
which  the  receiver  is  cut  off  and  weighed  with  its  contents, 
and  again  weighed  after  thoroughly  cleansing  out  the  mer- 
cury, when  the  loss  will  correspond  to  the  weight  of  the  lat- 
ter. If  nitric  acid  be  present  in  the  compound  to  be  ana- 
lyzed, quicklime  cannot  be  employed,  but  copper  turnings 
must  be  used  instead.  (Makins.) 

With  soluble  compounds  of  mercury  the  latter  may  be  esti- 
mated as  a  sulphide.  For  this  the  solution  is  to  be  acidula- 
ted with  hydrochloric  acid  and  excess  of  hydrogen  sulphide 
passed  in  ;  allow  the  precipitated  sulphide  to  subside,  and 
then  filter,  wash  quickly  with  cold  water,  and  dry  at  a  mod- 
erately low  temperature  and  weigh.  The  drying,  however,  is 
more  safely  and  accurately  performed  under  a  drying  glass 
with  sulphuric  acid  under  the  same  glass  for  absorption  of 
moisture,  trying  the  assay  on  the  scales  until  the  weight  is 
uniform. 


ANTIMONY. 

ANTIMONY.  As  a  metal  it  is  tin-white  and  volatile,  very 
brittle,  and  easily  reduced  to  powder.  It  has  been  reported 
as  native  at  Warren,  New  Jersey,  and  at  Prince  William, 
New  Brunswick,  Canada,  but  rare. 

Hardness  about  3;  gravity  6.6  to  6.7.  When  native, 
said  to  be  associated  with  silver,  iron,  or  arsenic.  Melting- 
point  1150°  R  (621°  C.). 


228  MINERALS,   MINES,   AND   MINING. 

But  the  chief  ores  are  the  sulphide  known  as  STIBNITE,  con- 
taining 71.8  antimony,  28.2  sulphur,  and  YALENTINITE,  or 
white  antimony,  which  seems  to  be  derived  from  the  other 
by  the  oxidation  of  the  ore.  There  is  also  a  red  antimony 
or  KERMESITE.  The  first  is  the  usual  ore. 

STIBNITE  occurs  both  in  masses  and  in  crystals,  the  latter 
with  the  sides  deeply  striated ;  lustre  metallic ;  often  colum- 
nar, and  color  and  streak  a  steel  gray,  or  lead  gray,  some- 
times iridescent.  It  is  sectile,  the  hardness  being  only  2  and 
gravity  4.5  to  4.6. 

Before  the  blowpipe  on  charcoal  it  fuses,  gives  off  both 
sulphurous  and  antimonial  fumes,  and  coats  the  coal  white 
with  oxide  of  antimony ;  the  latter,  treated  by  the  R.  F.,  tinges 
the  flame  a  greenish  blue.  It  is  perfectly  soluble  in  hydro- 
chloric acid. 

It  occurs  in  the  United  States  in  very  large  deposits  at 
San  Emigdio,  Kern  Co.,  California,  where  it  had  been  worked 
for  silver  many  years  ago.  The  vein  consists  of  quartz  and 
gray  antimony,  and  traverses  granite  rock,  northwest  and 
southeast,  with  a  dip  southwest  of  64°.  The  width  of  the 
vein  varies  from  a  few  inches  to  many  feet. 

At  the  Alta  claim  in  San  Benito  County,  there  is  a  dis- 
tinctively formed  vein  traversing  a  trachytic  or  plutonic 
rock.  The  thickness  varies  from  one  inch  to  twenty-four 
inches,  and  the  deposits  in  this  region  seem  to  be  very  great. 

Antimony  is  associated  with  cinnabar  in  several  places  in 
California. 

It  has  been  found  in  Nevada  about  twelve  miles  south  of 
Battle  Mountain  station,  on  the  Central  Pacific  Road,  in 


ANTIMONY.  229 

Humboldt  Co.  Here  the  veins  are  nearly  vertical  and  one 
hundred  feet  apart. 

Remarkable  deposits  of  stibnite  have  also  been  found  in 
Utah.  Here  the  antimony  occurs  just  above  the  junction 
of  the  sandstone  with  the  limestone  and  the  conglomerate ; 
and  in  some  places  the  ore  has  been  found  in  the  con- 
glomerate, penetrating  irregularly  between  the  boulders,  and 
without  the  evidence  of  any  vein  formation.  One  mass  of 
pure  stibnite  weighed  about  3000  pounds,  and  was  sent 
to  Salt  Lake  and  thence  to  New  York.  This  mass,  like 
most  of  the  ore  found  in  the  sandstone,  has  a  very  strongly 
defined  radial  structure,  the  crystallization  being  in  close 
aggregations  of  long,  needle-like  fibres,  or  prisms,  which 
are  diverted  from  central  points  or  nuclei,  giving  a  stellate 
appearance  to  the  masses,  and  particularly  to  the  smaller 
aggregations,  some  of  which  are  only  a  few  inches  in 
breadth.  In  the  large  masses  the  radial  fibres  are  some- 
times 18  inches  long,  and  form  dense  aggregations  of  pure 
ore  8  to  15  inches  thick  at  the  large  end,  tapering  to  a  point 
at  the  other  end.  (W.  P.  Blake,  in  the  Min.  Res.  of  U.  S., 
1885.) 

It  is  found  in  various  foreign  lands,  and  recently  some 
very  fine  crystals  have  been  sent  from  Japan  from  the  mines 
in  Shikoku  to  the  Yale  College  collections.  It  has  also 
been  worked  in  Nova  Scotia,  Sonora,  Mexico ;  France, 
Spain,  Portugal,  Prussia,  Austria,  Bohemia,  Hungary,  Italy, 
and  Algeria.  In  Victoria  a  lode  traverses  Silurian  strata, 
and  contains  about  2  ounces  of  gold  to  the  ton. 


230  MINERALS,    MINES,   AND   MINING. 

Extraction.  The  extraction  of  antimony  from  its  ores  is 
attended  with  some  difficulty,  owing  to  its  volatility  and 
affinity  for  oxygen.  If  the  sulphide  is  much  mixed  with 
veinstone,  such  as  quartz,  it  is  subjected  to  the  preliminary 
process  of  liquation,  by  which  the  fused  sulphide  flows  away, 
leaving  the  rock  behind.  The  sulphur  is  extracted  by  heat- 
ing with  iron,  alkalies,  and  charcoal,  leaving  a  regulus  of 
metal,  or  by  oxidation,  leaving  the  antimony  in  the  condi- 
tion of  teroxide,  which  is  afterwards  reduced  with  charcoal 
and  alkalies  in  crucibles.  The  metal  sinks  to  the  bottom, 
and  the  overlying  residue  is  known  as  crocus  of  antimony. 
(Blake.) 

Uses  of  antimony.  Antimony  is  used  extensively  in 
forming  type  metal,  the  amount  of  antimony  being  from  17 
to  20  per  cent.  Britannia  metal  contains  about  from  10  to 
16  parts,  and  Babbitt  metal,  for  journals  and  various  bearings 
of  machinery,  contains  8.3  per  cent.  Pewter  contains  about 
7  per  cent.,  and  various  metallic  compounds  of  softer  metals 
owe  their  hardness  to  certain  proportions  of  antimony. 
Besides,  it  is  used  in  medicinal  preparations,  in  pigments, 
and  in  vulcanization  of  rubber. 

Estimation  of  antimony.  A  method  of  quickly  making 
commercial  determination  of  antimony  present  in  ores,  alloys 
or  slags,  is  described  by  Mr.  G.  T.  Dougherty.  "  The  sub- 
stance is  first  reduced  to  a  button  by  fusion.  If  in  an 
oxidized  state,  it  is  melted  with  charcoal  and  argol;  if 
combined  with  sulphur,  it  is  decomposed  by  fusion  with 
equal  parts  of  potassium  cyanide  and  sodium  carbonate. 
Ten  grains  is  the  most  convenient  quantity  to  use.  The 


ANTIMONY.  231 

weighed  button  is  then  cut  into  small  pieces,  placed  in  a 
porcelain  dish,  and  digested  at  a  boiling  heat  in  a  mixture 
of  equal  parts  of  nitric  acid  and  water,  until  the  solution 
has  nearly  evaporated  and  the  lead  is  dissolved,  leaving  the 
antimony  as  a  white,  insoluble  precipitate  of  antimony 
tetroxide  (Sb2O4),  which  is  separated  by  filtration  from  the 
diluted  solution,  and  is  dried  and  weighed."  In  a  button 
containing  lead  and  antimony  only  the  quantity  of  lead  is 
ascertained  by  deducting  the  weight  of  the  antimony,  or  it 
may  be  determined  from  the  filtrate  as  sulphate  of  lead,  as 
we  have  shown  in  another  part  of  this  work. 
Composition  of  Sb2O4 : — 

Sb2  244  79.22  per  cent. 

04  64  20.78    "      " 

308  100.00    "      " 

To  distinguish  antimony  from  bismuth.  Treat  a  hydro- 
chloric solution  of  antimony  with  a  quantity  of  water,  an 
immediate  precipitate  of  an  oxychloride  falls.  This  may  be 
dissolved  in  tartaric  acid ;  the  addition  of  water  employed 
would  have  prevented  the  precipitation — it  now  dissolves  it. 
This  solubility  in  tartaric  acid  distinguishes  it  from  the  anal- 
ogous bismuth  precipitation. 

Makins's  method  of  estimating  antimony  is  very  satisfac- 
tory, as  follows :  To  the  hydrochloric  solution  add  a  little 
tartaric  acid  and  then  pass  in  dihydric  sulphide  (hydrogen 
sulphide).  Thus  the  sulphide  of  antimony  is  thrown  down. 
And  now  all  excess  of  the  precipitant  must  be  got  rid  of  by 
driving  it  off  at  a  temperature  of  about  100°  F.  Wash, 


232  MINERALS,   MINES,    AND   MINING. 

dry,  and  weigh  the  sulphide ;  having  noted  the  weight,  next 
dissolve  it  in  aqua  regia,  then  mix  this  with  a  solution  of 
tartaric  acid  and  precipitate  the  sulphuric  acid  (formed  by 
the  oxidation  of  the  sulphur  of  the  sulphide)  by  means  of 
chloride  of  barium.  From  the  weight  of  this  when  washed, 
dried,  and  ignited,  that  of  the  sulphur  is  got  at  and  the  loss 
represents  the  antimony. 

Caution. — In  passing  hydrogen  sulphide  through  the 
hydrochloric  solution  some  basic  antimony  chloride  may  re- 
main unless  fully  saturated,  and  with  gentle  heat  this  secures 
all  as  antimonious  sulphide. 


BISMUTH 

Occurs  native,  with  occasional  traces  of  arsenic,  sulphur, 
and  tellurium.  The  chief  ore  is  the  native  metal. 

Hardness,  2  to  2.5  ;  gravity,  9.7.  Lustre,  metallic. 
Streak  and  color,  silver-white  with  a  reddish  hue.  Brittle 
when  cold,  somewhat  malleable  when  heated.  It  crystal- 
lizes in  rhombohedra,  nearly  approaching  the  cube.  These 
may  be  formed  artificially  in  beautiful  masses  by  melting  a 
quantity  of  the  metal  in  a  ladle  or  a  pot  and  after  removing 
it  into  some  glowing  coals  or  heated  sand,  allowing  the  bulk 
to  cool  slowly ;  and  in  order  to  prevent  the  cooling  action 
commencing  at  the  upper  surface,  the  heat  is  kept  up  by  cov- 
ering the  vessel  with  a  shallow  iron  basin  into  which  a 
quantity  of  hot  fuel  is  placed.  As  soon  as  a  crust  of  metal 
is  presumed  to  have  formed  round  the  sides  and  top  it  is 


BISMUTH.  233 

pierced  at  one  side  by  a  red-hot  iron  and  the  remaining  fluid 
metal  is  poured  out.  If,  then,  when  cold,  the  upper  covering 
be  sawn  off,  the  whole  interior  surface  will  be  found  to  have 
crystallized  in  most  regular  forms  of  hollow  cubes  and  tetra- 
hedra. 

Bismuth  fuses  at  507°  F.  =  264°  C.,  and  when  added  to 
other  metals  it  lowers  their  melting-points  in  an  extraordi- 
nary manner.  At  a  high  temperature  it  burns  somewhat 
like  zinc,  with  a  bluish  flame,  giving  off  fumes  of  yellow- 
oxide. 

Nitric  acid  dissolves  the  metal  readily,  sulphuric  acid  only 
upon  boiling,  and  hydrochloric  acid  has  but  little  action 
upon  it. 

It  expands  on  cooling  after  fusion  to  about  one-thirty- 
second  of  increase  in  bulk. 

Detection  of  bismuth.  Its  salts  are  for  the  most  part  de- 
void of  color  ;  some  are  soluble,  others  insoluble ;  the  soluble 
salts  redden  litmus  paper. 

Dihydric  sulphide  or  ammonio-hydric  sulphide  throws 
down  a  black  sulphide,  insoluble  in  excess  of  either  precip- 
itant. 

The  alkalies,  potash,  soda,  or  ammonia,  throw  down 
white  hydrated  oxide.  Upon  boiling  this  precipitate  it  be- 
comes yellow. 

Potassic  chromate  throws  down  a  yellow  chromate  of  bis- 
muth, which  may  be  distinguished  from  the  corresponding 
lead  precipitate  in  being  soluble  in  dilute  nitric  acid  and  in- 
soluble in  caustic  potash. 

To  distinguish  it  from  lead,  sulphuric  acid  or  soluble  sul- 


234  MINERALS,    MINES,   AND   MINING. 

phates  produce  no  precipitate,  and  if  we  evaporate  with 
sulphuric  acid  in  excess  to  dryness  the  residual  mass  will  be 
perfectly  soluble  in  water  acidified  with  a  little  sulphuric 
acid. 

Under  the  blowpipe  a  salt  of  bismuth  heated  upon  charcoal 
with  sodic  carbonate  in  the  inner  or  reducing  flame  yields  a 
bead  of  the  metal,  surrounded  by  a  crust  of  yellow  oxide. 
This  may  be  distinguished  from  lead  by  the  brittleness  of 
the  bead  under  the  hammer.  The  yellow  crust  is  the  sesqui- 
oxide  and  is  of  a  deep  orange  color  while  hot,  but  yellow  on 
cooling. 

It  occurs  in  the  United  States  twelve  miles  west  of  Beaver 
City,  Utah,  in  a  magnesium  limestone,  but  the  entire  matter 
assays  only  from  one  to  six  per  cent,  of  the  metal.  Also  in 
Granite  district,  Beaver  County.  It  occurs  in  several  places 
in  Colorado,  in  Lake  City  district,  and  near  Golden  some 
rich  specimens  have  been  found.  Also  near  Tucson,  Ari- 
zona, and  in  Inyo  County,  California ;  and  some  remarkably 
pure  specimens  have  been  reported  as  found  on  the  flank  of 
Mount  Vostovia,  Alaska.  There  is  no  commercial  produc- 
tion of  bismuth  in  the  United  States  as  yet,  though  the 
prospects  are  fair,  and  a  producing  mine  would  be  valuable. 

Metallic  bismuth  is  used  in  making  fusible  alloys,  as  soft 
solder,  plugs  for  safety-valves,  and  in  stereotype  moulds. 
Also  as  an  amalgam  in  silvering  glass  globes.  The  sub- 
nitrate  is  used  under  the  name  of  pearl-white  as  in  enamels, 
in  porcelain,  in  optical  glass,  and  in  medicine.  The  nitrate 
is  used  as  a  mordant. 


CHROMITO.  235 


CHROMIUM. 

The  only  useful  ore  of  chromium  is  that  known  as  chrome- 
iron  or  iron-stone,  which  is  a  mixture  of  sesquioxide  of  chro- 
mium with  oxide  of  iron  and  whose  composition  may  be  ex- 
pressed by  the  formula  FeO2O4,  but  the  chromium  may  in 
part  be  replaced  by  iron  and  the  latter  may  be  partly  replaced 
by  magnesium.  Aluminum  is  sometimes  present,  and  silica 
may  be  found  in  the  sand  ore,  or  ore  containing  chromite  in 
the  form  of  small  grains.  The  purest  ore  is  sometimes  found 
in  lumps  weighing  several  pounds. 

The  mineralogical  name  is  chromite,  which  in  its  typical 
form  contains  32  parts  oxide  of  iron,  68  parts  oxide  of  chro- 
mium, but  in  analysis  may  contain  as  high  as  36  parts  oxide 
of  iron,  39.51  sesquioxide  of  chromium,  13  sesquioxide  of 
aluminum,  and  10.60  silica,  which  proportions  are  found  in 
a  Baltimore  specimen. 

Hardness  5.5;  grav.  4.32  to  4.56.  Lustre  submetailic, 
streak  brown,  color  between  iron  black  and  brownish-black. 
Brittle,  sometimes  magnetic. 

Before  the  blowpipe.  In  the  O.  F.  infusible ;  in  the  I.  F. 
becomes  slightly  rounded  on  the  edges,  and  then  is  found  to 
be  magnetic.  With  borax  and  salt  of  phosphorus  it  gives 
beads,  which,  while  hot,  show  only  a  reaction  for  iron,  but 
on  cooling  become  chrome-green ;  the  green  color  is  height- 
ened by  fusion,  on  charcoal,  with  metallic  tin.  (Dana.) 


236  MINERALS,    MINES,   AND   MINING. 

Not  soluble  in  acids;  soluble  with  heat  in  bisulphate  of 
potash,  or  soda. 

Its  occurrence  was  first  noticed,  in  the  commercial  way, 
many  years  ago  at  Bare  Hill,  Maryland,  but  these  deposits 
became  exhausted,  and  very  large  deposits  were  found  in 
Harford  and  Cecil  Counties,  Maryland,  and  in  Lancaster 
County,  Pennsylvania.  The  ore  is  extremely  infusible,  but 
after  many  improvements  the  final  results,  as  at  present 
understood,  lead  to  the  following  treatment:  The  decompo- 
sition of  the  ore  is  effected  by  powdering  the  mineral  by 
means  of  good  millstones,  heating  it  for  some  hours  in  a  re- 
verberatory  furnace  with  potassium  carbonate  and  lime  in 
certain  proportions,  and  dissolving  out  the  chromium  from 
the  fused  mass  by  water,  in  the  form  of  potassium  chromate, 
which  is  converted  into  bichromate  by  sulphuric  acid. 
Although  this  is  put  down  in  the  text-books  as  an  easy  pro- 
cess, it  requires  great  experience  and  skill  to  effect  results 
which  will  make  the  reductions  perfect,  and  at  such  rates  as 
will  compete  in  the  world's  markets.  This  the  skilled  firm 
in  Baltimore,  Maryland,  by  its  long  experience  and  by  de- 
vices known  to  itself  is  able  to  do. 

Recently  deposits  of  chrome  ore  have  been  found  in  Jack- 
son County,  North  Carolina,  also  in  Fairfax  County,  Virginia. 
But  the  largest  deposits  are  now  found  in  California,  in  Del 
Norte  County,  in  Sonoma,  San  Louis  Obispo,  and  in  Placer 
counties,  and  in  many  other  counties  of  California. 

These  deposits  are  not  found  in  veins,  but  in  pockets,  and 
may  at  any  time,  in  certain  locations  now  rich,  become  ex- 


CHROMIUM.  237 

hausted ;.  hence  it  is  important  to  keep  up  the  supply  by  ad- 
ditional discoveries. 

IN  THE  QUANTITATIVE  analysis  of  chrome  iron  ore  the 
assay  should  be  reduced  to  the  finest  powder  possible,  and 
time  is  saved  by  paying  careful  attention  to  this  work. 
Bisulphate  of  potassium  is  added  in  about  three  times  the 
weight  and  slowly  fused  with  it  in  a  platinum  crucible  at  red 
heat;  here  again  patience  and  long-continued  heating  must 
be  had  until  with  the  smooth  glass  rod  or  platinum  wire  no 
particles  can  be  felt.  Alkaline  carbonate  will  not  do,  but 
caustic  potassa  with  one-third  caustic  soda  will  in  a  longer 
time  make  a  good  solution.  The  fused  mass  is  extracted 
with  water,  which  dissolves  the  chromate  of  potassium  together 
with  the  excess  of  potassa;  the  oxide  of  iron  remains  behind, 
together,  perhaps,  with  a  small  quantity  of  the  undecomposed 
ore  if  the  fusion  at  first  was  not  complete ;  and  this  must  be 
separated  from  the  sesquioxide  of  iron  by  hydrochloric  acid; 
from  the  hydrochloric  solution  the  iron  is  precipitated  by 
ammonia,  and  the  chromic  acid  in  the  aqueous  solution  is 
reduced  to  the  sesquioxide  of  chromium  by  hydrochloric  acid 
and  addition  of  a  little  alcohol.  If  the  mineral  contained 
alumina,  it  will  be  found  in  the  aqueous  solution  with  the 
alkaline  chromate,  and  it  will  be  precipitated  together  with 
the  oxide  of  chromium,  from  which  it  is  separated  in  the 
following  way:  After  taking  the  weight  of  the  chromium 
oxide  and  alumina  compound,  fuse  the  mixture  as  in  the 
case  of  the  chrome  iron  assay  at  first ;  convey  the  precipitate 
(obtained  by  adding  ammonia  to  the  solution)  containing  the 
two  oxides  (chromium  and  aluminum)  into  a  hot  concentrated 


238  MINERALS,    MINES,   AND   MINING. 

solution  of  caustic  potassa,  and  boil  the  whole  down  till  near 
solidification ;  when  quite  cold,  water  is  added,  and  the  whole 
of  the  alumina  dissolves  without  carrying  with  it  a  trace  of 
oxide  of  chromium.  (Schaffhaeutl.) 


COBALT. 

This  metal  is  not  used  in  the  metallic  state,  but  when  re- 
duced to  that  state  it  is  usually  associated  with  nickel,  since 
the  nickel  ores  contain  cobalt.  As  nickel  is  slightly  mag- 
netic the  cobalt  ores  are  in  some  cases  also  very  slightly 
magnetic,  but  only  from  the  presence  of  nickel. 

The  ores  are  sulphoarsenide  (COBALT  GLANCE)  and  tin- 
white  arsenide  of  cobalt  (SMALTINE).  ZAFFRE  is  an  impure 
oxide  formed  by  roasting  the  ore  with  twice  its  weight  of 
quartz  sand.  The  metal  itself  may  be  prepared  by  first  roast- 
ing the  ore  at  a  moderate  temperature,  in  order  to  get  rid  of 
as  much  arsenic  as  possible.  It  is  next  dissolved  in  nitro- 
hydrochloric  acid,  evaporated  to  dryness,  and  the  residue 
dissolved  in  water.'  The  solution  is  then  precipitated  by 
dihydric  sulphide ;  thus,  all  metals  except  the  cobalt  and  iron 
go  down.  After  filtering,  the  clear  liquid  is  boiled  with  a 
little  strong  nitric  acid  in  order  to  peroxidize  the  iron,  after 
which  potassic  carbonate  is  added  to  throw  the  whole  down. 
Then  after  washing  this  precipitate  it  is  digested  in  oxalic 
acid,  which  converts  the  cobaltous  carbonate  into  an  insolu- 
ble oxalate,  while  it  dissolves  out  the  iron.  After  washing 
the  cobalt  salt,  intensely  heating  it  in  a  porcelain  cruci- 


COBALT.  239 

ble  will  at  once  reduce  the  metal.  The  crucible  must  be 
encased  in  a  clay  one,  as  the  heat  must  not  only  be  as  strong 
as  can  be  well  commanded,  but  must  also  be  maintained 
from  three-quarters  of  an  hour  to  an  hour.  (Makins.)  The 
heat  should  be  nearly  that  for  reducing  iron  ore. 

Cobalt  is  a  reddish-gray  metal,  crystalline,  with  specific 
gravity  8.95 ;  fusible  at  a  temperature  somewhat  below  that 
of  iron. 

Various  cobalt  minerals  have  been  found  where  neither 
the  amount  of  the  mineral  nor  the  per  cent,  of  cobalt  would 
pay  for  the  working,  but  they  occur  in  Carroll  Co.,  Maryland, 
in  Colorado,  at  Granite,  in  New  Mexico,  in  Nevada,  and  at 
Mine  la  Motte,  Missouri.  The  important  source  has  been  at 
the  nickel  mine  at  Lancaster  Gap,  Penn.  As  mined  the 
per  cent,  of  cobalt  is  only  0.1,  and  only  the  nickel  associated 
with  it  gives  any  profit  in  the  working. 

The  only  use  at  present  for  cobalt  is  as  a  pigment — to 
give  color  to  glass,  to  correct  the  yellow  color  in  pottery,  and 
in  decoration  work. 

Attempts  have  been  made  to  plate  with  cobalt  as  with 
nickel,  but  they  have  shown  its  inferiority,  because  cobalt 
plating  oxidized  more  rapidly  than  nickel  and  was  more 
costly. 

The  metallic  value  of  cobalt,  nominally,  is  $14  per  pound. 
Cobalt  oxide  has  varied  from  $2.50  to  $3  for  twenty  years, 
except  at  one  period,  lately. 

Compounds  of  this  metal  may  be  detected  under  the  blow- 
pipe by  the  intense  blue  they  give  in  the  oxidizing  flame,  in 
borax. 


240  MINERALS,   MINES,    AND   MINING. 

The  separation  of  cobalt  from  nickel  is  a  very  nice  opera- 
tion, requiring  care.  The  solution  of  the  protoxides  of  these 
metals  must  be  free  from  other  oxides,  those  of  potassium  and 
sodium  excepted ;  hydrocyanic  acid  in  excess,  and  then  caustic 
potassa  are  added;  it  is  then  warmed  until  all  is  dissolved,  when 
it  becomes  a  reddish-yellow  in  color.  It  is  then  heated  to  boil- 
ing, to  expel  excess  of  hydrocyanic  acid.  A  double  cyanide  of 
cobalt  and  potassium  is  first  formed,  which  is  next  converted 
into  cobalticyanide  of  potassium,  hydrogen  being  evolved. 
The  double  cyanide  of  nickel  and  potassium  is  unchanged. 
Some  mercuric  oxide  (red  oxide)  is  now  powdered,  washed, 
and  added,  and  the  mixture  boiled.  '  The  nickel  is  precipi- 
tated partly  as  nickelous  oxide,  and  partly  as  cyanide,  mercu- 
ric cyanide  being  produced  and  at  the  same  time  passing  into 
solution.  The  nickel  precipitate  is  now  washed  and  ignited, 
and  the  residue  being  a  pure  nickelous  oxide,  a  dirty  grayish- 
green-powder,  is  weighed  and  estimated.  Composition,  NiO 
=  59  +  16  =  75.  Ni  78.67  per  cent.,  021.33.  (Liebig.) 

The  cobalt  in  the  filtrate  may  now  be  determined  by  first 
nearly  neutralizing  by  nitric  acid,  then  adding  a  solution 
of  mercurous  nitrate  as  neutral  as  possible ;  a  precipitate 
now  falls  which  is  mercurous  cobalticyanide ;  this  washed, 
ignited,  and  weighed,  is  pure  cobaltous  oxide  [the  per  cent. 
of  cobalt  being  78.67].  (Wohler.) 


CORUNDUM   AND   EMERY.  241 


CORUNDUM  AND  EMERY. 

CORUNDUM  when  pure  is  simply  alumina,  or  sesquioxide 
of  aluminum,  and  emery  in  its  general  acceptance  is  the 
same  with  various  degrees  of  associated  iron  oxide  (ferric  or 
ferrous  oxide).  Corundum  in  its  purest  crystalline  state  is 
the  sapphire  when  blue,  and  ruby  when  red.  But  the 
hardness  (pure)  varies  from  next  to  the  diamond  9,  to 
(impure)  as  low  as  5,  the  latter  being  emery  much  mixed 
with  magnetite  and  silica.  Its  gravity  if  pure  is  about  4. 
Lustre  vitreous,  sometimes  pearly  on  the  basal  planes,  and 
frequently,  as  in  North  Carolina  specimens,  showing  an 
opalescent  star  of  six  rays  in  the  direction  of  the  axis,  espe- 
cially if  dipped  in  water. 

Under  the  blowpipe  it  remains  unaltered,  but  slowly 
dissolves  in  borax  and  salt  of  phosphorus  to  a  clear  glass 
colorless  if  free  from  iron.  The  finely  pulverized  mineral, 
after  long  heating  with  a  cobalt  solution,  gives  a  beautiful 
blue  color.  It  is  converted  into  a  soluble  compound  if 
heated  with  bisulphate  of  potash  as  in  case  of  chrome  iron 
ore  last  described. 

This  mineral  is  associated  with  crystalline  rock,  as 
granular  limestone,  or  dolomite,  gneiss,  granite,  mica,  slate, 
chlorite  slate. 

The  largest  occurrence  of  emery  at  present  known  is  at 
Chester,  Mass.,  but  this  emery  is  not  rated  as  equal  to  the 
foreign,  nor  at  all  equal  in  abrasive  power  to  corundum, 

16 


242  MINERALS,   MINES,   AND   MINING. 

especially  to  that  now  worked  in  North  Carolina  at  Corun- 
dum Hill,  Macon  County,  and  in  Georgia,  Lowndes  County, 
and  in  other  States.  In  searching  for  corundum,  chlorite  is 
considered  a  good  sign.  "As  the  rocks  of  the  southern 
corundum  field  are  often  decomposed  to  a  depth  of  from  80 
to  40  feet,  prospecting  is  sometimes  difficult ;  but  a  careful 
preliminary  examination  of  the  surface  will  often  save  much 
useless  digging."  Hence  it  is  advised  to  look  for  corundum 
neither  in  the  gneiss  nor  in  the  chrysolite  (?),  but  along  the 
contacts  of  the  two  rocks,  and  particularly  when  the  two 
rocks  are  most  altered  :  if  a  contact  is  found,  it  should  be 
carefully  followed  and  the  adjacent  rocks  closely  examined. 
(T.  M.  Chartard.)  This  chrysolite  is  a  term  probably  for 
some  eruptive  rock  or  hypersthene  of  grayish-green  color, 
but  not  the  true  chrysolite,  mineralogically. 

Almost  all  the  corundum  and  a  large  proportion  of  the 
emery  of  commerce  are  used  for  the  manufacture  of  the  well- 
known  corundum  and  emery  wheels.  The  preparation  of 
corundum  and  emery  has  for  its  object  the  granulation  of 
the  material  into  a  series  of  "numbers"  or  grades  of  fineness, 
ranging  from  the  finest  "  flour"  up  to  particles  of  compara- 
tively large  size. 

The  method  recommended  to  test  the  abrasive  power  of 
a  corundum  sample,  upon  which  its  value  depends,  is  by  tak- 
ing a  piece  of  plate  glass  previously  weighed,  placing  on  it 
a  weighed  portion  of  the  sample  to  be  tested,  rubbing  the 
material  on  the  glass  and  continuing  the  operation  until  the 
glass  ceases  to  lose  in  weight,  the  total  loss  in  weight  of  the 
glass  giving  the  abrasive  power  of  the  sample.  (Chartard.) 


PUMICE    STONE.  243 

The  proper  way  of  conducting  this  test  is  by  using  two 
pieces  of  glass  one  to  rub  with  and  the  other  to  be  weighed, 
or  both  may  be  weighed  and  the  time  taken  in  constant 
work  is  also  an  element  in  making  up  a  test. 

Corundum  beds  may  be  considered  valuable  and  the  value 
will  increase.  The  exports  of  manufactured  emery  in  1883 
were  reported  in  value  as  $1857,  and  in  1887  there  were 
exported  emery  wheels  valued  at  $35,290 ;  emery  cloth, 
emery  paper,  and  corundum  wheels  $4537 ;  total  $39,827. 
The  imports  for  the  same  year  were :  Emery  ore,  $66,601 ; 
emery  in  grains,  ground,  pulverized,  or  refined,  $29,833 ; 
emery  wheels  or  files,  $1191 ;  total,  $97,625. 


PUMICE  STONE. 

The  only  deposit  of  this  material  utilized  in  the  United 
States  is  near  Lake  Merced,  a  few  miles  from  San  Francisco, 
California,  but  the  amount  mined  is  very  small,  not  exceed- 
ing seventy  tons  yearly,  but  of  a  quality  equal  to  the  im- 
ported article. 

Pumice  stone,  as  imported  from  the  Lipari  Islands,  is  com- 
posed of  from  70  to  77  per  cent,  silica,  and  16  to  17.5  of 
alumina  with  a  little  (.5  to  1.75)  ferric  oxide  and  some  lime 
and  potassa.  In  gravity  it  is  lighter  than  water  and  gene- 
rally of  a  grayish  color,  occasionally  brownish-gray.  Lipari, 
a  volcanic  island,  twenty-six  miles  north  of  Sicily,  is  at  pres- 
ent the  great  magazine  of  pumice  stone.  The  value  of  the 
importation  of  this  substance  in  1883  was  $50,634,  decreasing 
in  1887  to  $26,291. 


244  MINERALS,   MINES,   AND   MINING. 

Rotten  stone,  sometimes  known  as  "  tripoli,"  is  a  decom- 
posed silicious  limestone,  not  yet  discovered  in  any  sufficient 
quantities  for  mining  in  the  United  States,  but  is  imported 
from  Great  Britain,  $2235  worth  being  entered  for  con- 
sumption  in  1886,  and  $5556  in  1887.  The  knowledge  of 
these  two  bodies  must  be  gained  by  comparison  of  samples 
known  with  the  mineral  samples  obtained. 


INFUSORIAL  EARTH. 

The  composition  of  this  material  is  chiefly  of  what  may 
be  called  the  minute  silicious  skeletons  of  fossil  animalcules 
(infusoria).  The  analysis  of  infusorial  earth  near  Richmond, 
Virginia,  yielded  Mr.  J.  M.  Cabell  75.86  of  silica,  9.88  alu- 
mina, some  ferric  oxide  and  smaller  quantities  of  lime,  mag- 
nesia, potash,  soda,  and  nitrogenous  matter.  The  detection 
of  this  earth  must  be  made  by  use  of  the  microscope,  which 
readily  reveals  the  silicious  fossils. 

Beds  of  this  earth  have  been  found  in  many  places  in 
California  and  Nevada,  some  of  which  have  been  proved  to 
be  of  great  extent. 

This  earth  has  been  used  in  the  manufacture  of  polishing 
powders,  in  so-called  "  sand  soaps"  and  other  detersive  soaps, 
and  as  an  absorbent  of  nitro-glycerine  for  explosives,  although 
for  the  latter  purposes  it  has  been  imported  from  Germany. 
A  deposit  known  as  "tripoli"  is  found  on  the  Patuxent 
River,  near  Dunkirk,  Calvert  County  ,-Maryland.  Samples 
show  about  84  per  cent,  silica,  one  specimen  running  over 


GRINDSTONES — BUHR-STONES.  245 

90  per  cent,  with  about  8  per  cent.  lime.     Work  has  begun 
quite  extensively  upon  this  deposit. 


GRINDSTONES. 

This  is  a  fine-grained  sandstone  differing  greatly  in  tex- 
ture and  hardness  in  different  localities.  The  principal 
source  of  grindstones  in  the  United  States  is  the  geological 
formation  known  as  the  Berea  Grit,  which  underlies  large 
areas  in  the  northeastern  part  of  Ohio.  Near  Grindstone 
City,  Michigan,  there  is  found  a  fine-grained  argillaceous 
stone,  of  a  uniform  blue  color,  which  is  in  general  use  for 
finishing  work,  especially  where  a  very  fine  edge  is  required. 
Near  Marquette,  on  the  shore  of  Lake  Superior,  the  writer 
discovered  a  large  quantity  of  an  exceedingly  fine-grained 
silicious  sandstone  of  close  texture  and  had  some  of  it  worked 
up  in  Ohio,  where  it  was  made  into  small  stones  of  excellent 
cutting  power,  and  it  is  probable  that  as  soon  as  arrange- 
ments can  be  made  the  material  will  be  more  extensively 
tried.  In  1884  the  total  imports  finished  and  rough  were 
7056  tons,  valued  at  $86,286.  But  the  home  production 
was  valued  as  $570,000  in  the  same  year.  In  1887  the 
imports  were  $37,548. 


BUHH-STONES. 

The  leading  localities  for  this  stone  in  the  United  States 
are  Ulster  Co.,  New  York,  where  the  stone  known  as  Esopus 


24:6  MINERALS,   MINES,    AND   MINING. 

stone  is  a  quartzite  of  variable  texture  and  hardness ;  Lan- 
caster Co.,  Pennsylvania,  here  called  the  Cocalico,  a  con- 
glomerate stone  found  as  bowlders  scattered  over  the  sur- 
face ;  Peninsula,  Summit  Co.,  Ohio,  where  a  white  variety 
of  the  Berea  Grit  is  worked,  mainly  for  the  purpose  of  grind- 
ing oatmeal  and  barley.  Many  other  places  have  reported 
discoveries  of  buhr-stones  of  various  qualities,  but  the  Amer- 
ican stones  are  not  used  at  all  for  grinding  wheat,  but  only 
for  the  coarser  cereals,  and  for  grinding  paints,  cement, 
chemicals,  fertilizers,  charcoal,  etc.  The  imported  stones, 
being  finer  in  grain  and  much  harder,  are  used  for  grinding 
wheat  and  for  all  the  better  class  of  work.  The  use  of  roll- 
ers, as  a  substitute  for  buhr-stone,  is  gaining  ground  with 
great  rapidity,  and  this  may  account  for  the  fact  that,  while 
in  1882  the  value  of  buhr-stones  imported  was  $104,034,  in 
1883  it  fell  to  $73,685,  and  in  1887  to  $26,217.  The  true 
buhr-stone  is  a  cellular  flinty  rock  having  the  nature,  in  part, 
of  coarse  chalcedony.  (Dana.) 


THE  DIAMOND. 

Diamonds  have  been  found  in  the  following  places  in  the 
United  States:  Probably  the  largest  was  found  at  Man- 
chester, Virginia,  in  some  earth  dug  up  by  a  laboring  man, 
the  first  public  record  of  which  occurs  in  the  New  York 
Evening  Post  of  April  28,  1855.  The  original  weight  was 
23f  carats,  and  after  cutting  it  weighed  ll|i  carats  (carat 


THE    DIAMOND.  247 

of  four  grains).  As  it  is  an  "off  color"  and  not  perfect, 
its  present  value  is  considered  only  $300  to  $400. 

The  first  diamond  found  in  North  Carolina  was  at  the 
ford  of  Brindletown  Creek,  in  Burke  County,  value  $100. 
Another  was  found  in  the  same  neighborhood  and  a  third 
at  Twitty's  mine,  Rutherford  County,  of  yellowish  color. 
A  fourth  was  found  near  Cottage  Home,  Lincoln  County, 
in  1852,  and  of  greenish  color.  Another  was  found  at 
Todd's  branch,  Mecklenburg  County,  of  a  good  white  color. 
Dr.  Andrews  reports  the  finding  of  a  black  diamond,  of  the 
"  size  of  a  chincapin,"  by  three  persons,  who  crushed  it, 
believing  a  diamond  could  not  be  broken.  He  found  that 
the  fragments  scratch  corundum  very  readily. 

The  following  places  may  be  mentioned  in  addition: — 

Two  diamonds  found  at  Portis  mine,  Franklin  County, 
N.  C. 

One  at  head-waters  of  Muddy  Creek,  McDowell  County, 
N.  C. 

Several  from  one-half  carat  to  over  2  carats,  J.  C.  Mill's 
mine  in  Burke  County,  but  some  of  these  were  quartz,  and 
one  Mr.  Kunz  found  to  be  zircon. 

"  The  diamonds  found  in  North  Carolina  are  usually 
found  associated  with  gold,  monazite,  xenotime,  zircon, 
octahedrite,  and  other  minerals."  (Kunz.)  Dr.  Genth  says 
this  debris  is  the  result  of  the  old  gneissoid  rocks,  such  as 
mica  schists  and  gneiss,  in  which  graphite  is  always  found. 
Monazite  has  a  hardness  of  5  to  5.5  and  gravity  of  about  5, 
with  a  resinous  lustre,  with  a  brownish  or  yellowish-brown 
color,  and  subtranslucent  to  nearly  transparent  appearance. 


248  MINERALS,   MINES,    AND   MINING. 

The  composition  is  phosphoric  acid,  thorium,  sometimes  tin, 
cerium  and  lanthanum;  the  mineral  is  very  rare:  Under 
the  blowpipe  it  is  infusible,  but  soon  turns  gray,  and  with  a 
little  sulphuric  acid  it  tinges  the  flame  bluish-green  :  With 
borax  it  gives  a  bead  yellow  while  hot  and  colorless  on  cool- 
ing, and  a  saturated  bead  becomes  enamel  white  on  flaming, 
soluble  in  muriatic  acid  with  difficulty.  Xenotime  has  the 
same  general  appearance,  except  that  it  is  opaque,  hardness 
4  to  5,  gravity  4.5;  its  composition  is  phosphoric  acid  and 
yttria,  and  acts  under  the  blowpipe  as  monazite,  but  is 
insoluble  in  acids :  the  crystals  are  frequently  flattened, 
while  those  of  monazite  are  rather  elongated.  Octahedrite 
has  a  hardness  of  monazite  and  a  gravity  4,  a  metallic- 
adamantine  lustre,  color  various  shades  of  brown,  passing 
into  indigo  blue  and  black ;  greenish-yellow  by  transmitted 
light,  uncolored  streak,  and  is  in  composition  pure  titanic 
acid.  Before  the  blowpipe  infusible,  but  with  salt  of  phos- 
phorus gives  a  colorless  bead  which  in  the  I.  F.  assumes  a 
violet  color  on  cooling.  Where  any  iron  is  present  the 
color  appears  only  upon  charcoal  when  treated  with  metal- 
lic tin.  If  made  soluble,  by  fusion  with  an  alkali  or  alkaline 
carbonate,  in  excess  of  muriatic  or  nitric  acid,  with  the 
addition  of  tin-foil,  it  gives  a  beautiful  violet  color  when 
concentrated,  just  as  in  the  case  of  the  mineral  rutile,  which 
has  the  same  composition.  See  Titanium. 

Mr.  C.  Leventhorpe  mentions  the  finding  at  his  placer 
mine,  in  Rutherford  County,  North  Carolina,  of  a  diamond 
of  bad  color,  which  was  placed  in  the  Amherst  College  col- 
lection. 


THE    DIAMOND.  249 

One  was  found  in  a  South  Carolina  placer  by  Mr.  T  witty, 
and  one,  owned  by  the  latter  gentleman,  from  White  County, 
Georgia.  Also  in  Georgia  at  the  Horshow  placer  gold  mine, 
Racooche  Valley,  White  County,  Georgia,  several  have  been 
found  here. 

Also  in  California  from  Forrest  Hill,  El  Dorado  County, 
found  at  a  great  depth  in  the  auriferous  gravel.  Another  at 
French  Carrol,  Nevada  County.  Four  have  been  found  at 
Fiddletown,  Amadort  County,  in  the  gray  cemented  gravel 
underlying  a  stratum  of  so-called  lava,  or  compact  ashes. 
Prof.  Whitney  states  that  diamonds  had  been  found  in  fifteen 
to  twenty  localities  in  California,  the  largest  of  7^  carats,  found 
at  French  corral.  Some  13  or  14  have  been  reported  from 
Placer ville,  California.  At  Cherokee  flat,  some  fifty  or  sixty 
diamonds  have  been  found,  some  rose-colored  and  yellow, 
and  some  white,  all  associated  with  lava,  ashes,  or  other 
volcanic  matter,  zircon,  platinum,  iridium,  magnetite,  etc. 

A  few  have  been  found  in  the  placer  diggings  in  Idaho. 
One  was  said  to  have  been  found  at  Eagle,  Waukesha 
County,  Wisconsin,  having  been  thrown  out  from  a  depth 
of  60  feet  while  excavating  a  well.  Two  others  have  been 
reported  as  found  here.  One  was  found  at  Nelson  Hill, 
near  Blackfoot,  Deer  Lodge  County,  Montana,  and  another 
near  Philadelphus,  Arizona. 

Diamonds  have  a  gravity  of  about  3.5.  When  found 
they  are  generally  of  an  octahedral  shape,  and  without  any 
very  apparent  lustre,  hence  they  must  be  cut  before  the 
characteristic  brilliancy  exhibits  itself.  They  will  bear  even 
a  red  heat  without  losing  any  hardness,  or  even  suffering 


250  MINERALS,   MINES,   AND   MINING. 

injury  in  any  way.  While  resisting  pressure  to  a  remarkable 
extent,  they  may,  however,  be  fractured,  and  frequently 
diamonds  have  been  splintered,  or  broken,  under  the  stamp 
of  the  gold  quartz  stamp  at  the  mills.  Perhaps  one  of  the 
best  tests  of  a  diamond  is  its  ability  to  scratch,  or  wear,  the 
surface  of  a  piece  of  corundum.  The  appearance  of  the 
diamond  in  the  rough  state  is  so  peculiar  that  nothing  but 
large  experience  will  enable  the  discoverer  of  such  a  diamond 
to  determine  its  nature.  But  as  corundum  is  next  in  hard- 
ness to  the  diamond,  the  latter  in  a  rough  state  will  show 
its  nature  very  frequently  by  its  feeling  of  resistance  as  well 
as  by  its  effect  upon  the  corundum  surface.  But  this  feeling 
of  resistance  is  to  a  great  extent  only  acquired  by  experience, 
and  hence  only  the  abrasive,  or  scratching  power  of  the  true 
diamond  upon  a  smooth  piece  of  corundum  is  a  sure  test. 
The  octahedral  form  of  the  diamond,  as  sometimes  found,  is 
not  always  to  be  expected  by  the  explorer,  since  it  frequently 
occurs  in  other  forms,  and  sometimes  massive  in  small  quan- 
tities, and  has  been  found  in  various  shades  of  color  and 
even  black.  But  we  may  be  almost  certain  that  any  per- 
fectly crystalline  transparent  forms  are  not  those  of  the  true 
stone,  especially  if  projecting  from,  or  attached  to,  any  rock. 
Diamonds  are  found  always  of  a  dingy  white  surface  and 
sometimes  like  ground  or  worn  glass  pebbles,  unless  they 
have  suffered  fracture.  Their  ability  to  scratch  glass  is  no 
proof  of  their  distinctive  value  as  diamonds,  and  other  trans- 
parent stones  found  with  the  diamonds  may  do  the  same, 
especially  the  zircon  and  quartz  pebbles. 


THE    DIAMOND.  251 

In  the  diamond  fields  of  Africa  it  is  said  that  the  richest 
stones  are  found  in  a  bed  of  clay  about  200  feet  below  the 
surface,  and  as  the  claims  are  about  300  yards  square  the 
work  is  very  expensive,  for  miners  attempt  to  excavate  and 
examine  the  entire  claim,  since  fine  diamonds  may  be  found 
in  any  part.  This  is  at  Kimberley,  Griqua  land. 


PART  II. 


MINING  WORK  AND  ARCHITECTURE 


INCLUDING 


VARIOUS  SUGGESTIONS,  WITH  DESCRIPTIONS  OF  ASSOCIATED 
APPARATUS  AND  MACHINERY. 


WITH    AN    APPENDIX 


OH 


BQRKG  ARTESIAN,  PETROLEUM,  GAS,  AM)  OTHER  DEEP  WELLS. 


MINING  CONSTRUCTION  AND  MACHINERY. 


INTRODUCTION. 

IN  this  part  we  have  followed,  to  a  large  extent,  the 
plans  and  suggestions  of  some  of  the  best  English,  French, 
and  German  authorities  and  works,  but  especially  the  work 
of  Niederist,  which,  in  translating,  we  have  accommodated 
to  methods  adopted  successfully  in  our  own  mines.  In  some 
parts  of  New  York  and  in  mines  on  Lake  Superior  as  well  as 
in  the  South  and  in  the  Colorado  and  Montana  gold  mines, 
a  system  of  mining  was  formerly  pursued,  with  a  view  to 
immediate  results,  which  has  been  the  occasion  of  great  loss 
of  products  as  well  as  of  time,  and  has  necessitated  great 
labor,  in  some  instances,  to  put  the  workings  into  shape 
for  future  operations.  The  author  had  photographs  and 
drawings  taken  as  illustrations  of  these  errors;  it  was  thought, 
however,  best  not  to  use  them,  but  to  present  only  the  best 
methods,  as  the  reasons  for  adopting  them  would  cover  all 
instances  of  errors  and  of  inferior  plans  and  apparatus  and  so 
afford  more  space  for  that  which  might  prove  more  valuable. 

The  cuts  will  fully  explain  all  the  suggestions  and  meth- 
ods presented  where  the  text  has  not  already  given  descrip- 
tions. 


256  MINERALS,  MINES,  AND  MINING. 

SOME  EXPLANATION  OF  TERMS. 

Various  names  are  given  to  the  same  parts  of  mines  as 
well  as  of  pieces  of  construction,  in  different  parts  of  the 
country.  These  variations  are  readily  learned  at  the  place,  and 
do  not  cause  much  confusion  to  the  well-informed.  Certain 
terms,  however,  are  almost  universal,  and  a  few  of  these 
should  be  understood  before  we  proceed. 

Niederest  and  other  German  authors  give  the  German 
names  we  have  stated,  which  in  some  cases  are  better  than 
the  usual  English  names. 

Fig.  7.  A  gallery,  or  gangway,  is  a  horizontal,  or  slightly 
ascending  subterranean  entrance  into  a  hill  or  mountain. 

Its  beginning,  $,  is  called  the  opening  or  mouth  and  is 
usually  understood  as  the  opening  to  daylight  (miindlock  or 
miindung).  The  upper  part  is  called  the  roof,  sometimes 
the  range  (firste  or  forste) ;  the  lower  part  the  floor,  or  bot- 
tom (sohle)  ;  both  right  and  left  sides  are  called  the  side- 
walls  (ulme),  and  the  end  of  the  gallery  in  the  mountain,  t, 
is  the  termination  or  end  of  the  mine  (ort,  or  vorort). 

Every  gallery  nook  which  does  not  open  out  directly  into 
day,  A,  A,  is  called  by  the  German  miner  a  strecke,  and  when 
transportation  is  the  object  of  such  a  gallery  it  is  called  a 
run,  or  course,  or  way  (lauf).  It  is  the  Austrian  solilen- 
strecke,  or  in  the  Cumberland  region  of  England  the  head- 
way. Sometimes  it  is  called  the  heading  gangway,  as  in  the 
Eastern  Pennsylvania  coal  regions. 

If  this  latter  gangway,  H  or  F,  driven  in  a  formation  com- 
posed of  layers,  runs  at  right  angles  with  the  strike  of  the 


FIG.  7. 


FIG.  10. 


FIG.  11. 


FiG.l! 


To  face  page  256. 


PRELIMINARY   WORK   AND    CONSIDERATIONS.  257 

vein,  that  is,  runs  parallel  with  the  dip,  or  inclination,  it  is 
called  an  inclined  drift,  or  heading  (scliwebende  strecke); 
sometimes  in  England  an  "  upbrow"  or  "  drift  on  the  dip" 
and  an  "  inclined  drift,"  or  heading.  If  it  follows  the  strike 
of  the  strata,  that  is,  runs  parallel  with  the  strike,  it  is  called  a 
"  strike  gallery"  or  "  way  run  on  the  gallery"  and  it  is  called 
a  diagonal  strike  when  made  upon  a  line  between  the  two 
directions  above  described. 

If  from  a  gallery,  or  gangway,  S  T,  a  branch,  A.  A,  sets 
off  sidewise,  it  is  called  a  level  (fliigelort),  or  when  it  passes 
along  the  strike  of  the  deposit  the  Germans  call  it  an  "  aw- 
1  an  gen"  or  side  level  or  side  way.  If  the  gallery,  or  "  strecke" 
runs  crosswise  into  the  mountain  or  bed,  it  is  called  a  "  cross- 
cut," and  may  be  either  an  "  overhanging"  cut,  H,  or  "  un- 
derlying" cut,  Z,  according  to  the  position  of  the  rock  as  a 
hanging  or  lying  rock,  i.  e.,  hanging  or  foot  rock.  When  a 
gallery  crosses  another  as  at  K,  or  crosses  the  side  level  (or 
auslangen),  only  the  term  "  crossing"  is  used  to  express  this 
fact.  (See  Fig.  7.) 

Other  terms  which  are  used  in  this  work  are  generally 
explained  in  the  text  or  the  figures. 

PRELIMINARY  WORK  AND  CONSIDERATIONS. 

Trial  shafts  or  excavations  are  in  some  cases  necessary 
before  the  main  work  of  mining  proper  begins.  In  the 
brown  hematite  ores  these  trial  shafts  are  generally  made 
where  the  country  is  higher  on  one  side,  and  the  general 
appearance  of  the  immediate  site  of  the  shaft  is  that  of  a 

17 


258  MINERALS,   MINES,    AND   MINING. 

shelf  or  of  a  basin.  In  many  places  these  hematites  seem  to 
have  originated  from  the  washing  down  of  red  hematites, 
and  of  magnetic  ores  from  higher  levels,  and  the  long-con- 
tinued settling  of  the  hydrated  ore  upon  some  knee,  or  on 
some  basin.  In  such  cases,  borings  by  proper  machinery 
may  take  the  places  of  regular  excavations,  as  in  a  shaft. 

When,  however,  the  mineral  sought  for  is  known  to  exist 
in  sufficient  quantities  and  determination  is  settled  to  begin 
excavation,  the  first  important  examination  is  to  be  made  of 
the  immediate  neighborhood  to  learn  the  general  level  and 
the  nearest  distance  to  some  run  or  rivulet,  and  such  other 
descents  as  shall  determine  the  question  of  drainage  if  it 
should  so  happen  that  the  mine  should  ever  be  troubled  with 
water. 

A  study  of  the  nature  of  the  soil  should  be  instituted  with 
a  view  to  the  choice  of  the  material  and  the  quantity  to  be 
used  in  protecting  the  excavations,  and  a  wise  provision 
made  beforehand  for  the  timber,  or  masonry,  which  may  be 
called  for  in  course  of  work. 

One  of  the  most  important  elements  of  successful  mining 
is  accessibility  to  market.  This  includes  accessibility  to 
those  places,  furnaces  or  mills,  to  which  in  the  nature  of  the 
product  the  ore  or  rock  should  be  transported  before  ready 
for  the  market.  Such  methods  by  river,  or  rail,  or  road,  should 
be  diligently  studied  before  any  true  mining  work  is  begun. 
There  is  no  one  point  in  which  economy  may  be  studied 
with  better  advantage  than  in  the  cost  of  transportation, 
both  within  the  range  of  the  works  and  beyond.  Unneces- 
sary grades,  bad  clayey  or  rough  roads,  cost,  in  the  long  run, 


PRELIMINARY   WORK   AND   CONSIDERATIONS.  259 

heavily  by  delay,  breakage,  and  wear  and  exhausted  power 
and  small  amount  of  carriage,  all  necessitated  by  the  condi- 
tion of  the  way  over  which  products  are  carried. 

When  the  work  of  excavating  or  mining  proper  is  to  be 
begun,  a  very  important  consideration  to  be  taken  into  ac- 
count is  that  relating  to  drainage.  In  some  cases  mining  may 
be  prosecuted  in  a  region  where  little  water  is  found.  In 
other  cases  no  exit  by  gravitation  may  be  had,  so  that  by 
any  grade,  water  may  flow  out  of  the  mine ;  and  then  the 
only  resort  is  a  pit,  in  the  proper  place,  to  receive  the  drain- 
age, from  which  pit  the  water  must  be  lifted  to  the  surface 
by  some  power  to  be  hereafter  stated.  But  in  all  cases  the 
system  of  inclination  called  the  grade  must  be  definite  and 
thoroughly  provided  for  at  the  beginning,  and  all  works  con- 
structed and  excavations  made  with  a  view  to  this  descent, 
which  will  be  more  or  less  modified  according  to  circum- 
stances. 

This  grade  or  descent  of  the  floor  is  modified  somewhat, 
by  the  nature  of  the  rock  or  earth  forming  the  floor,  or  by  its 
smoothness  and  the  amount  of  water  to  be  drained.  As  we 
shall  see  hereafter,  the  drain  or  sluice  through  which  the  mine- 
water  runs  may  be  constructed  along  the  middle  of  the  floor, 
or  on  either  side,  and  should  always  be  sufficiently  wide  and 
deep  to  prevent  overflowing  the  floor.  The  amount  of  grade 
or  descent  will  be  from  one-eighth  of  an  inch  to  one-half  of 
an  inch  per  yard  of  length — the  former,  when  the  water  is 
not  great  in  quantity,  and  the  channel  smooth.  Generally, 
a  quarter  of  an  inch  to  the  yard  is  descent  enough.  The 
main  gallery  is  usually  constructed  along  the  strike  of  the 


260  MINERALS,   MINES,   AND   MINING. 

mineral  to  be  mined.  The  location  of  the  gallery,  or  limiting 
of  the  side  walls,  will  depend  much  upon  the  strength,  the 
soundness  and  the  size  of  the  mineral  vein,  lode  or  seam  to 
be  worked.  So  also  will  the  number  and  position  of  the 
galleries  be  determined  by  the  size  and  location  of  the  vein 
or  seam.  It  may  be  necessary  to  increase  the  number  of 
galleries,  and  they  will  then  be  distinguished  by  numbering 
them  as  first,  second,  etc.,  gallery  or  "  lift" — upper,  middle, 
or  lower  gallery;  according  to  number  and  position. 

Opening  a  gallery  from  the  side  of  a  hill,  all  other  things 
being  equal,  is  preferable,  as  may  readily  be  seen  by  Fig.  8. 

Here  it  becomes  plain,  that  there  would  be  an  advantage 
gained  for  drainage  and  transportation  by  "driving"  a  gallery 
into  the  hill-side  toward  the  vein  which  is  represented  as 
slightly  inclining  or  pitching  downward  from  right  to  left,  AB. 

In  opening  upon  a  lode  or  vein  which  pitches  as  above 
stated,  it  is  always  best  to  begin  the  galleries,  in  this  case 
called  drifts,  near  the  top  of  the  hill  and  work  toward  the 
lode  or  vein.  The  second  gallery  or  drift,  below,  will  be 
under  the  first  at  a  distance  determined  by  the  softness  of 
the  soil,  and  the  amount  of  vein  (on  the  slope)  which  can  be 
economically  worked.  For  there  must  be  considerable  ex- 
pense incurred  in  running  these  drifts,  as  they  are  to  be 
made  wide  and  high,  and  thoroughly  prepared  for  conveying 
the  material  from  the  mines  and  for  drainage.  If  the  mineral 
vein  can  be  worked  upward  from  any  one  drift  floor,  the 
distance  from  the  floor  of  one  drift  gallery  to  that  one  over 
it  may  be  determined  in  part  by  the  economic  amount  of 


PRELIMINARY   WORK   AND    CONSIDERATIONS.  261 

labor  capable  of  being  done  upward.  As  this  is  strictly  a 
matter  of  economy  it  must  be  studied  upon  the  basis  of  what 
may  be  said  hereafter. 

All  galleries  running  at  right  angles  to  the  above  drifts 
must  incline  toward  the  drift  according  to  the  suggestions  on 
p.  259.  They  will  then  be  galleries  running  parallel  with  the 
strike  of  the  mineral  dip  and  be  worked  along  the  face  of 
the  dip  or  inclined  plane. 

It  is  evident  that  a  slope  might  be  sunk  from  the  top  of 
the  hill,  Fig.  8,  within  the  lode  A  J3,  or  vein,  if  the  lode 
was  wide  enough,  and  no  drifts,  CD,  E  F,  G  H,  be  made, 
but  only  galleries  (strike  galleries)  upon  the  vein,  and  along 
it  parallel  with  the  face  of  the  hill,  and  having  the  vein  as  both 
floor  and  roof,  or  they  might  be  only  partly  in  the  vein,  or  the 
gallery  might  be  outside  of  the  vein  entirely.  Figs.  9,  10, 
and  11  will  explain. 

Fig.  9  represents  the  gallery  entirely  in  the  lode  to  be 
worked  out  The  lode  A  B  is  wide  enough  for  the  gallery, 
the  roof  is  weak,  hence  it  is  timbered,  as  represented.  The 
side  walls,  hanging,  and  foot  walls  are  alone  strong. 

Fig.  10  represents  a  case  where  this  gallery  is  partly  in 
the  rock  and  partly  in  the  lode.  If  the  lode  is  weak,  then, 
timber  on  the  side — the  hanging  rock  is  strong  and  you  can 
trust  it  for  roofing ;  or  when  the  rock  pitches  timber  your 
soft  lode  rock,  as  in  Fig.  11,  putting  the  gallery  outside  of 
the  lode  entirely. 

Fig.  12  represents  the  gallery  entirely  within  the  lode 
when  the  lode  rock  is  the  only  safe  rock,  or,  as  in  Figs.  13 
and  14,  when  the  rock  is  not  in  horizontal  strata;  being,  Fig. 


262  MINERALS,    MINES,   AND   MINING. 

13,  partly  in  gangue  rock  and  partly  in  the  mine  rock,  but 
having  the  hanging  rock  in  a  part  resting  upon  the  upper 
timbering.  In  Fig.  14  advantage  is  taken  of  the  lode  rock 
for  the  entire  top  of  the  gallery,  and  the  gallery  floor  is  laid 
upon  the  outside  or  gangue  rock.  In  all  these  cases  the 
miner  will  be  guided  in  the  timbering  by  the  nature  of  the 
rock.  In  some  cases  the  lode  will  be  timbered,  in  others 
the  outside  rock,  as  in  the  figures. 

In  some  cases  it  will  be  found  advantageous  to  build  a 
gallery  parallel  with  the  "  pay  rock,"  and  yet  some  eighty 
or  ninety  feet  off,  more  or  less,  according  to  circumstances, 
and  connect  the  pay  rock  with  the  gallery  by  offset  drivings, 
EEEE)  Fig.  15,  wherein  A  B  represents  the  pay  rock  or  lode, 
CD  the  gallery,  and  E  E  E  E  the  drivings.  In  this  and  in  sim- 
ilar cases  the  miner  must  timber  where  necessary,  and,  indeed, 
either  timbering  or  stone  work  would  be  required  in  such  a 
case  as  this,  for  here  the  pay  rock  is  supposed  to  be  strong 
and  the  neighboring  rock  untrustworthy,  and  it  is  desirable, 
perhaps,  to  extract  all  the  pay  rock. 

In  general  it  is  advisable  to  follow  all  curves  in  the  pay 
rock  or  seam  by  most  gradual  turns  in  the  gallery,  which  is 
the  plan  above  suggested,  and  may  be  easily  accomplished,  as 
the  distance  between  AB  and  CD  will  allow  of  curves  of 
greater  or  lesser  intensity  even  when  the  pay  rock  A  B  sud- 
denly changes  its  course.  Thus  all  severe  bends  or  changes 
of  direction  in  tramways  and  other  methods  of  transit,  either 
to  or  fro  along  the  gallery,  unnecessary  obstructions  to  the 
easy  flow  of  air  in  ventilation,  and  other  objectionable  feat- 
ures of  mine  operation,  may  be  avoided. 


FIG.  13. 


FIG.  15. 


FIG.  16. 


PLATE  II. 

FIG.  14. 


FIG.  18. 


FIG.  17. 


FIG.  19. 


To  face  page  262. 


PRELIMINARY   WORK   AND   CONSIDERATIONS.  263 

In  all  mining  operations  more  or  less  water  (mine  water) 
may  be  met  with.  Sometimes  it  increases  gradually,  at 
other  times  with  more  or  less  suddenness,  and  the  water 
channels  of  the  earth  may  be  likened  to  the  great  system  of 
blood-passages  or  channels  in  the  human  body.  In  general, 
where  the  water  enters  the  excavations  in  large  quantities,  a 
channel  may  be  let  into  the  floor  of  the  gallery  and  covered, 
as  in  Fig.  16.  Or,  if  the  water  supply  is  not  large,  it  may 
be  led  off  on  either  side,  as  in  Figs.  17  and  18,  though  in 
general  the  water  gutter  or  channel  should  be  made  on  the 
side  which  cuts  into  the  down  or  lower  slope  of  the  rock,  as 
most  water  is  found  at  that  side.  Wherever  the  channel  is 
likely  to  leak,  and  it  is  not  thought  proper  to  allow  the  mine 
water  to  escape  into  the  rock,  the  channel  may  be  either 
clayed,  timbered,  or  regularly  tiled  or  covered  with  mason 
work,  as  may  be  found  suitable.  (Fig.  18.)  For  here  it 
should  be  carefully  noticed  that,  as  in  Fig.  17,  where  a 
fissure  occurs  in  the  rock,  it  is  always  unwise  to  allow  water 
to  run  along  the  drain  over  such  a  fissure,  for  the  percolation 
of  water  through  fissures  may  lead  to  extra  work  in  some 
unexpected  direction,  and  the  work  of  removing  or  even  lift- 
ing the  same  water  may  be  found  necessary  on  some  lower 
level  where  gravitation  may  add  to  the  cost  of  removing 
that  water  which  now  might  readily  and  with  little  extra 
pains  be  carried  entirely  beyond  the  mine. 

Where  expedition  is  required  the  miner  may  run  a  drift 
into  the  side  of  a  hill  on  the  proper  grade,  and,  while  a  set 
of  men  are  at  work  toward  the  shaft,  another  set  may  be 


264  MINERALS,    MINES,   AND   MINING. 

working  downward  or  from  the  shaft  A  B  toward  the  first 
set  at  (7,  as  illustrated  in  Fig.  19. 

Between  the  several  galleries  built  over  each  other  there 
may  be  a  vertical  distance  of  from  60  to  120  feet  thickness, 
but  the  lowest  gallery  may  run  beneath  the  level  of  the 
water  outside,  in  which  case,  the  water  not  being  able  to 
run  off,  will  accumulate  and  must  be  extracted  by  pumps. 
Generally  the  place  at  the  bottom  of  the  main  shaft — a 
square  hole  several  feet  deep — is  called  the  sumpt  (correctly 
sumpf),  and  into  the  hole  all  the  drained  water  runs  by 
gravity.  The  main  or  principal  passage  may  be  called  the 
gallery,  and  the  parallel  galleries,  above  and  below,  may  be 
called  the  first,  middle,  and  lowest  lift,  course,  or  gangway, 
as  in  Fig.  20.  Where  more  than  three  occur  other  names 
are  used. 

In  some  mines  it  is  necessary  to  make  many  short  or  long 
drifts  or  oreways  into  the  side  of  the  shaft  between  the  usual 
lifts,  and  it  has  been  recommended  to  draw  not  only  the  ore 
and  other  minerals  from  these  secondary  drifts  or  levels,  but 
also  the  water,  by  methods  described  hereafter,  as  a  means  of 
saving  cost  upon  the  process  of  drawing  all  waters  from  the 
foot  of  the  shaft  whither  they  have  been  led  by  all  the 
drains  from  all  passages  whatever.  Before  any  steam  pumps 
are  placed  it  would  be  undoubtedly  best  to  pump  all  waters 
and  raise  all  dead  (useless)  rock  and  all  useful  material  from 
the  least  depth  as  a  matter  of  true  economy.  But  in  the 
advanced  state  of  pumping  machinery,  where  large  pumps 
can  be  obtained  at  all,  very  little  additional  cost  will  pur- 
chase pumps  capable  of  forcing  water  from  great  depths, 


PLATE  III. 


FIG.  20. 


FIG.  21. 


A  B 


FIG.  23. 


FIG.  24. 


To  face  page  264. 


PRELIMINARY   WORK   AND   CONSIDERATIONS.  265 

where  any  attempt  to  save  expense  by  lifting  or  forcing  from 
two  or  more  levels  by  distinct  pumps  would  be  an  expense 
without  any  corresponding  profit. 

Where,  from  the  level  nature  of  the  country,  no  entrance 
upon  the  mineral  lodes  can  be  made  by  drifts,  or  any 
horizontal  passages,  it  is  necessary  to  adopt,  from  the  begin- 
ning, the  SHAFT  method  of  reaching  the  objects  of  search 
and  of  mining.  These  shafts  may  be  intended  for  various 
purposes  and  may  be  worked  from  several  points  and  places 
both  above  and  under  ground  in  a  mine  region.  They  may 
be  for  many  purposes,  but  they  may  be  divided  into  the 
main,  or  head  shaft,  or  hoist,  and  into  secondary  shafts  for 
the  purposes  of  connecting  the  ends  on  floor  and  roof  of  two 
galleries  or  gangways.  In  some  mines  they  are  worked 
from  below  upwards  or  from  above  downward,  the  former 
being  a  very  dangerous  and  inconvenient  method  when  the 
soil  is  loose,  in  which  latter  case  it  becomes  dangerous  even 
to  dig  downwards,  except  where  the  lower  gallery  roof  is 
sustained  by  a  propped  ceiling,  when  the  miner  may  dig 
down,  making  the  danger  less  imminent  as  he  descends, 
rather  than  increasing  it,  as  in  the  former  case.  When 
rock  is  to  be  penetrated  it  is  possible  to  drill  from  below 
upward  and  from  above  downward,  although  even  then  it 
is  doubtful  in  some  cases  whether  it  is  economical  to  work 
upward,  and  in  all  cases  it  is  attended  with  danger  from 
pieces  of  rock  half  detached  falling  upon  the  workman. 

Where  the  shaft  is  intended  for  the  entrance  of  light,  and 
opens  to-day,  it  is  called  the  day-shaft,  but  such  a  shaft  is 
rarely  opened.  Generally,  the  main  shaft  towards  which  all 


266  MINERALS,   MINES,   AND   MINING. 

the  underground  drains  run,  is  the  one  at  the  foot  of  which 
is  a  deep  cistern  or  reservoir  into  which  are  received  the 
mine  waters  and  which  is  called  the  sumpt,  and  in  many 
cases  it  occupies  the  spot  immediately  over  the  "  carriage" 
or  box  used  to  let  the  men  down  and  bring  up  the  ore  or 
coal.  It  is  more  out  of  the  way  here,  and  as  no  one  should 
ever  stand  under  the  carriage,  and  no  one  can  when  it  is  down, 
there  is  less  danger  of  getting  into  it  in  this  position  than  if 
put  in  any  other.  Nevertheless,  it  is  plain  that  when  slopes 
occur,  this  might  not  be  the  only  proper  or  convenient 
place. 

The  advantage  of  the  slope  over  the  perpendicular  shaft 
is  generally  apparent  when  by  the  slope  we  can  pass  down 
upon  the  dip  of  the  vein  or  along  a  line  lying  in  the  direc- 
tion of  the  strike — thus  taking  out  the  useful  mineral  from 
the  opening  of  the  mining  work.  For  it  is  evident  that 
compared  with  a  shaft  there  is  no  economy  of  time  or  dis- 
tance in  using  a  slope  to  reach  the  same  spot  in  the  mine, 
as  a  longer  way  is  to  be  traversed,  which,  in  a  long  run, 
seems  to  amount  to  much  useless  consumption  of  time  and 
power,, and  in  addition  involves  loss  of  material  in  wear  and 
tear  of  engine,  strain,  etc.  But  there  are  cases  where  the 
slope,  despite  these  disadvantages,  is  profitable,  especially 
where  there  is  no  dead  work  (work  yielding  no  mineral)  in 
driving  the  slope,  while  there  may  be  much  in  sinking  a 
shaft. 

A  cross  section  of  one  method  of  shaft-framing  may  be 
seen  in  Fig.  21. 

Here,  if  we  assume  the  general  proportions,  from  15  to  18 


PRELIMINARY   WORK   AND   CONSIDERATIONS.  267 

feet  long  and  6  feet  broad,  we  have  a  rectangular  opening 
in  the  rock,  or  loose  earth,  divided  into  four  compartments : 
A  for  the  mine  water  pump,  B  for  the  ascent  of  the  miners, 
and  CD  for  the  raising  of  material. 

This  is  probably  the  greatest  number  of  divisions,  and  an 
unnecessary  amount,  for  in  some  of  our  most  important  ore 
and  coal  mines  it  is  customary  to  make  but  two  grand  divi- 
sions, for  example,  making  the  A  division  both  a  pumping 
shaft  and  upcast,  and  of  the  division  B  both  hoist  way  for 
material  and  miners  and  downcast  for  ventilation  where  the 
ventilation  is  by  furnace.  In  the  latter  case,  six  by  ten  or 
eleven  feet  is  usually  sufficiently  large.  But  all  this  may  be 
yet  modified  by  particular  emergencies. 

In  beginning  and  in  the  prosecution  of  a  shaft,  it  is  import- 
ant that  after  the  proper  location  has  been  decided  upon,  the 
exact  vertical  direction,  or  in  case  of  a  slope,  the  inclination 
should  be  exactly  and  continuously  preserved.  A  straight 
and  vertical  shaft  may  be  used  as  both  an  experimental  and 
permanent  shaft,  though  originally  built  only  to  determine 
the  direction  of  the  vein  or  the  slope  or  dip  of  the  mineral 
seam  ;  thus  in  Fig.  22  we  have  an  illustration. 

When,  however,  as  partly  suggested  in  Fig.  22,  the  ore, 
lode,  or  seam  appears  of  undetermined  angle,  it  is  more  eco- 
nomical to  sink  another  shaft,  more  as  a  trial  shaft,  between 
the  surface  points  A  H,  which  will  more  certainly  determine 
the  direction  of  the  slope  as  the  depth  will  always  be  much 
less  than  at  A.  If  successful,  the  shaft  may  for  some  pur- 
poses be  used  to  better  advantage  than  the  shaft  at  A. 

But  having  sunk  the  shaft  on  the  vertical  line  A  B  and 


268  MINERALS,   MINES,   AND   MINING. 

finding  the  vein  when  C  is  reached,  it  may  be  approximately 
determined  from  what  direction  the  seam  slopes  towards  (7, 
and  therefore  workmen  may  immediately  begin  to  drive  a 
gallery  at  C  while  others  work  out  a  drift  at  D  toward  E, 
or  at  F  toward  G.  In  a  slope  the  seam  or  dip  would  be- 
come itself  the  line  of  direction  for  the  work,  and  would  de- 
termine the  angle  of  inclination  of  the  vein,  as  seen  in  Fig. 
23. 

Here  SS  is  the  slope  sunk  to  A,  having  one  lift  or  gallery 
at  B,  and  the  mine  is  in  course  of  construction.  While  the 
above  methods  may  be  suitable  in  some  rocks,  in  others  the 
lode  or  gangue  may  be  so  unstable  or  weak  as  to  require  for 
safety  and  economy  that  the  shaft  be  sunk  as  in  Fig.  24  and 
approaches  be  made  to  the  material  to  be  worked  out  upon 
(in  this  case)  the  gradually  lengthening  gangways  CC  DD. 
Especially  is  this  so  when  the  lode  AB  is  on  a  very  steep  in- 
cline, as  in  Fig.  24. 

In  the  coal  beds  the  slope  would  be  put  down  along  the 
dip  of  the  coal,  which  would  be  represented  by  AB,  Fig. 
24. 

In  opening  the  shaft  in  rock  or  soil  it  is  recommended  to 
begin  at  a  narrow  end  or  the  shortest  side  of  the  rectangle  and 
blast,  or  open  out  toward  the  other  end,  always  sinking 
deeper  at  the  beginning  that  the  water  may  find  a  little 
sumpt  and  be  readily  pumped  out,  By  reference  to  Fig.  25, 
it  will  be  seen  that  either  slope,  or  shaft,  may  begin  with 
the  same  rectangular  space  upon  the  surface  of  the  ground 
at  AC,  but  the  long  side  will  generally  be  toward  the  engine 
or  machinery  for  pumping  or  raising.  The  reason  will  read- 


FIG.  86. 
0A  C  o 


FIG.  27. 


PLATE  IV. 

FIG.  26. 


FIG.  28. 


FIG.  29. 


FIG.  30. 


To  face  page  268. 


PRELIMINARY   WORK    AND   CONSIDERATIONS.  269 

ily  be  seen  by  noticing  the  divisions  in  Fig.  21,  for  no  chains 
or  pump-trunks  or  pipes  should  run  along  the  length  unless 
there  be  some  reason  compensating  for  the  expense  of  un- 
necessarily increased  ropes,  chains,  pipes,  etc.  After  suffi- 
ciently descending,  the  main  lift  or  galleries  can  be  com- 
menced, always  giving  a  fair  foothold  or  start  into  the  gal- 
lery before  the  shaft  is  continued  downward  below  the  foot, 
or  floor,  of  the  newly  begun  side  work.  Where  there  is  no 
special  expedition  called  for,  it  is  better  to  proceed  farther 
upon  the  new  level,  using  the  shaft  bottom,  now  at  level  with 
the  cross-cut  or  gallery,  for  the  place  whence  either  the  gangue 
rock  or  mineral  may  be  lifted  at  least  until  the  vein  is  fairly 
opened  upon,  and  the  cross-cut  finished,  or  dead  rock  re- 
moved. 

In  some  ore-gangways  opening  into  the  shaft,  it  is  recom- 
mended to  lower  the  level  or  floor  of  the  gangway  at  the 
mouth  or  opening  into  the  shaft  as  represented  in  Fig.  26, 
A,  thus  allowing  a  space  below  the  floor  level  for  delivering 
the  ore  out  of  the  way  of  the  gallery  level  where  it  may  be 
handled  before  delivering  into  the  shaft. 

Where  the  roof  is  weak  it  is  advised  to  sink  two  side  pits 
EE.  Put  solid  timber  up  in  these  pits  to  support  the  roof, 
and  then  remove  the  intervening  embankment  for  the  lowered 
level.  (See  ground  view,  Fig.  27.) 

It  may  be  timbered  as  in  the  elevation,  Fig.  28.  The 
usual  timbering  may  then  be  made  to  complete  the  safety 
and  usefulness  of  this  dumping  flat  or  depression. 

The  depth  of  this  dumping  floor  or  pit  might  be  five  or 
six  feet,  and  as  wide  as  the  shaft.  By  this  pit,  ore,  etc. 


270  MINERALS,   MINES,    AND    MINING. 

might  be  kept  below  the  level  until  all  hands  can  attend  to 
the  lifting.  This  is  a  German  method,  but  not  an  economi- 
cal one  in  all  cases,  especially  where  the  ore-cart,  running 
on  tramways,  may  be  filled  by  the  miners,  run  along  the 
gangway  to  the  shaft,  and  even  upon  the  floor  of  a  shaft- 
hoist,  or  cage  prepared  for  that  purpose,  thus  dispensing 
with  all  this  handling,  necessary  where  the  ore  is  thrown  into 
such  a  depression  at  the  shaft. 

In  some  shafts  where  the  water  is  troublesome  it  is  led  off 
from  the  side  walls  by  inclined  gutters  or  grooves  in  the  rock 
and  conducted  into  niches  or  recesses  in  the  side  of  the  shaft 
as  represented,  Figs.  29,  30,  where  it  may  be  retained  and 
from  which  it  may  be  pumped  before  going  further  down. 

The  abutments  A  B  are  either  of  stone  or  of  timber,  and 
the  spaces  between  them  and  the  sides  opposite  the  shafts 
are  made  wide  enough  to  allow  of  the  free  passage  of  the 
buckets,  miners,  etc.  Although  cases  may  occur  where  this 
method  may  be  adopted  with  advantage,  it  is  seldom  called 
for  except  when  an  outflow  at  some  particular  place  might 
cause  trouble  in  allowing  water  to  fall  down  the  shaft  and 
become  a  great  inconvenience. 

As  the  construction  of  the  shaft  and  horizontal  ways  is  of 
great  importance,  reference  is  made  to  other  parts  of  this 
treatise  where  this  very  important  art  in  mining  is  stated 
more  at  large. 

ON  THE  OPENING  OF  MINES. 

• 

In  order  to  reap  the  greatest  possible  advantage  from  a 
deposit  of  mineral  which,  after  preliminary  prospecting,  is 


ON   THE   OPENING   OF   MINES.  271 

deemed  sufficiently  rich  to  reward  the  labor  and  expense  of 
mining,  it  is  necessary,  first,  to  open  and  explore  the  deposit 
(bed,  vein,  lode,  or  mine),  that  is,  to  find  out  its  extent,  the 
thickness  and  richness  of  the  ore  or  mineral. 

As  long  as  a  vein,  or  lode,  runs  in  a  well-defined  shape 
and  size,  in  unbroken  connection  and  uniform  direction,  there 
is  no  difficulty  in  opening  and  exploring  the  mine.  All  that 
is  necessary  is  simply  to  follow  it.  But  it  is  frequently  the 
case  that  changes  and  interruptions  and  diverse  departures 
from  regularity  occur,  and  these  demand  not  only  a  general 
knowledge  of  mineral  deposits,  but  some  knowledge  of  the 
particular  country  where  a  mine  is  to  be  opened  and  much 
careful  observation. 

The  opening,  or  exploring  of  a  mine,  begins  really  with 
the  work  of  prospecting  and  is  only  a  continuation  of  that 
work.  One  of  the  most  important  general  rules  to  be  ob- 
served in  opening,  or  exploring  a  deposit,  is  to  follow  it  to  the 
end  in  its  two  main  directions,  namely,  its  horizontal  direc- 
tion, or  bearing,  and  its  inclined  direction,  or  dip,  and  this 
ought  to  be  done,  although  both  the  richness  and  the  thiclmess 
of  the  vein  decrease.  Another  rule  is  to  pay  constant  and 
close  attention  to  the  general  direction  of  the  vein,  the  nature 
of  the  mass  composing  the  vein,  and  also  the  nature  of  the 
sides.  If  the  vein  be  thin,  or  there  is  danger  of  losing  it, 
the  better  plan  is  to  begin  in  the  centre  of  the  exploring 
tunnel,  or  shaft,  and  from  that  part  note  carefully  every 
change.  The  most  important  changes  are:  (1)  the  splitting, 
forking,  or  scattering  of  a  vein;  (2)  the  compression,  or,  as 


272  MINERALS,    MINES,   AND   MINING. 

miners  call  it,  the  pinching  of  the  vein ;  and  (3)  shifts,  or 
faults. 

If  a  vein  divides  into  several  branches,  it  is  best  to  follow 
the  one  which  continues  in  the  main  direction,  more  especi- 
ally if  it  be  the  largest,  and  the  surrounding  rock,  or  gangue, 
correspond  to  the  undivided  vein.  The  remaining  branches, 
or  forks,  and  also  any  veins,  or  threads,  that  may  be  dis- 
covered in  either  wall,  are  reserved  for  a  future  investigation, 
and  to  indicate  their  location  they  are  cut  into  to  the  depth 
of  a  few  inches. 

If  a  vein  becomes  thin  or  pinched,  it  is  best  to  follow  what- 
ever traces  there  may  be  in  the  main  direction.  Sometimes  a 
vein  appears  pinched  out  because  the  "filling  up"  (or  "pay 
gangue")  leaves  the  main  seam  or  stratum,  and  the  ore  shifts 
from  one  side  to  the  other.  In  such  cases  it  is  best  to  attack 
the  seam  in  its  average  direction,  and  occasionally  to  work 
above  it  as  well  as  below. 

When  a  vein  or  lode  is  intersected  by  another  and  the 
continuation  of  the  one  that  is  in  process  of  opening  cannot 
be  found  in  the  same  direction,  and  when  there  is  conse- 
quently reason  to  suspect  a  shift  (slide,  fault),  then  the  first 
thing  to  be  done  is  to  examine  carefully  the  intersection,  to 
discover,  if  possible,  from  the  manner  in  which  the  vein 
enters  or  combines  with  the  dike  or  cross  vein,  on  which 
side  the  offcast  is  likely  to  be  found.  Should  this  remain 
doubtful,  then  the  intersecting  dyke  or  cross  vein  is  to  be 
followed  for  some  distance  in  both  directions,  being  careful 
to  observe  the  traces  of  the  gangue  rock,  closely  examining 
every  diverging  seam,  and  following  the  most  promising  until 


ON   THE   OPENING   OF   MINES.  273 

fully  convinced  that  all  has  been  examined.  It  is  sometimes 
the  case  that  the  intersecting  (transverse)  vein  wholly  takes 
up  the  mineral  sought  for,  so  that  no  offcast  or  only  a  very 
weak  one  is  found;  in  which  case  the  intersecting  vein  may 
itself  be  worth  mining. 

In  opening  a  deposit  of  mineral  it  must  be  remembered 
that  a  distinction  is  to  be  made  between  the  gangue  and  the 
ore,  for  the  latter  is  only  a  part  of  the  former,  still  it  pre- 
serves its  own  form  and  direction,  which  demand  special  at- 
tention. Thus,  for  example,  the  lenticular  mass  of  ore  A  B, 
Fig.  31,  is  at  different  levels  of  different  thickness  or  power, 
as  the  tunnels  CD  E  indicate,  and  because  of  the  rise  (in- 
clination) of  the  deposit,  the  tunnel  and  shafts  are  not  con- 
tinuously in  ore,  but  enter  sooner  or  later  into  the  barren 
overlying  or  underlying  rock.  Of  all  this  the  first  tunnel, 
with  its  upper  and  lower  levels,  ought  to  furnish  sufficient 
data  to  determine  where  the  limits  of  the  pay  ore  are  and 
how  far  it  is  proper  to  proceed  with  the  work  of  opening,  so 
as  not  to  incur  useless  expense  and  labor.  In  general  it  is 
a  good  rule  to  infer  the  unknown  from  what  is  well  known. 

The  rise  (inclination)  of  the  ore  requires  special  considera- 
tion in  opening  a  lower  or  foot  drift  or  adit.  If,  for  exam- 
ple, it  were  proposed  to  attack  the  ore-mass  A  B^  Fig.  31,  by 
means  of  an  adit  (drift)  from  the  point  F,  it  is  plain  that  the 
ore  would  not  be  reached,  but  the  adit  would  pass  below  it 
into  the  mountain.  Before  a  foot  adit  is  opened  there  must 
be  sufficient  evidence  to  show  that  the  ore  reaches  down  as 
low  as  the  level  on  which  it  is  intended  to  drive  the  adit  and 
that  it  has  not  already  been  pitched  away. 

18 


274  MINERALS,   MINES,    AND   MINING. 

To  determine  where  the  work  of  opening  a  deposit  is  to 
;  begin  and  how  it  is  to  be  carried  on  it  is  necessary  to  con- 
sider the  nature  of  the  ground  and  the  situation  of  the  de- 
posit. If  the  mountain  be  steep  and  the  strike  of  the  vein 
parallel  to  the  slope  of  the  mountain,  the  shortest  way  to 
attack  it  is  by  means  of  a  tunnel  from  the  slope  to  the  vein, 
unless  there  should  be  in  some  ravine  close  by  an  outcrop  or 
edge  which  would  make  the  deposit  more  accessible.  On 
reaching  the  deposit  by  means  of  a  cross-tunnel,  galleries  are 
made  in  it  to  the  right  and  left  and  shafts  are  sunk  in  the 
direction  of  its  dip. 

If,  however,  the  strike  of  the  vein  be  across  the  strike  of 
the  mountain  ridge,  then  the  work  of  opening  is  begun  on 
the  line  of  the  strike,  and,  if  possible,  at  a  point  where  it 
opens  out.  There  a  tunnel  is  driven  along  the  course  of  the 
vein  and  shafts  are  sunk.  The  tunnel  is  commenced  as  low 
down  as  the  known  depth  of  the  deposit  will  permit. 

If  the  deposit  to  be  opened  be  greatly  inclined  or  if  it 
strike  under  a  plain,  it  is  opened  by  sinking  two  inclined 
shafts  at  suitable  distances  from  each  other  in  the  direction 
of  its  fall  and  uniting  them  by  a  gallery.  Perpendicular 
shafts  may  also  be  substituted  for  the  inclined,  which  are 
sunk  in  the  overlying  or  hanging  rock,  provided  it  be  solid, 
but  if  not  of  sufficient  solidity  and  firmness  the  shafts  are 
sunk  in  the  underlying  rock,  and  in  both  cases  the  two 
shafts  are  brought  in  connection  with  the  deposit  by  means 
of  tunnels,  A  B,  Fig.  32.  The  shafts  should  be  sunk  in 
such  a  manner  as  to  pierce  the  deposit  at  a  medium  depth. 

A  deposit  or  bed,  nearly  horizontal,  which  lies  under  a 


PLATE  V. 


TIG.  31. 


FIG.  32. 


FIG.  33. 

D  F 


FIG.  34. 


A   f 


To  face  page  274. 


ON   THE   OPENING   OF   MINES.  275 

plain,  is  opened  by  means  of  two  perpendicular  shafts,  which 
shall  arrive  at  points  in  the  same  line  of  the  dip  not  in  the 
line  of  the  strike  and  which  are  united  by  a  tunnel  cut  in 
the  deposit. 

The  opening  of  large  irregular  deposits  is  nearly  the  same 
as  that  of  veins  and  beds;  only  this  is  to  be  remarked  that  it 
is  not  advisable  to  make  shafts  pass  through  standing  masses; 
it  is  better  to  put  the  shaft  some  little  distance  away  in  the 
barren  rock  and  open  the  deposit  by  means  of  tunnels 
driven  from  the  shafts. 

The  nests  or  kidneys  of  ore  lying  separate  from  each  other 
offer  the  greatest  difficulty  in  opening  and  preparing  them 
for  mining.  The  facts  by  which  the  miner  has  to  be  guided 
are  very  few  and  rather  vague.  As  a  general  rule  these  de- 
posits occur  in  a  narrow  strip  of  the  mountains  and  observe 
a  certain  direction ;  in  this  strip  the  rock  is  of  a  different 
nature  from  that  outside  of  it,  and  the  nests,  pockets,  or  de- 
tached masses  are  sometimes  connected  by  slender  seams  and 
traces  which  may  serve  as  guides.  Such  deposits  are  at- 
tacked by  means  of  a  tunnel  driven  to  their  lower  extrem- 
ity, or  by  a  shaft  sunk  in  the  immediate  neighborhood,  and 
they  are  mined  from  below  upward. 

Well-conducted,  scientific,  systematic  mining  requires  that 
the  opening  and  exploring  of  a  deposit  should  always  be  in 
advance  of  the  work  of  extracting  the  ore.  Moreover,  it  is 
important  not  to  continue  on  the  first  opened  level  until  that 
be  exhausted,  but  to  go  down  to  the  lower  parts  of  the  de- 
posit as  soon  as  practicable,  for  in  many  cases  the  ore  is  ex- 
tracted and  the  mine  exhausted  more  economically  from 


276  MINERALS,   MINES,   AND   MINING. 

below  upwards:  1st,  because. the  empty  spaces  in  the  higher 
levels  afford  free  course  to  the  water  and  thus  increase  the 
quantity  of  that  troublesome  element  which  becomes  more 
arid  more  annoying  the  deeper  the  mine  is  worked ;  2d,  be- 
cause it  is  much  more  difficult  to  support  spaces  formed  by 
working  from  above  downwards  than  the  opposite  ;  3d,  be- 
cause many  deposits  from  their  nature  are  more  easily  ex- 
hausted from  below  upwards. 

In  going  down  to  the  depth  of  the  deposit  necessary  pro- 
vision must  be  made  in  time  for  removing  the  water  from 
the  mine. 

Systematic  mining  also  requires  that  both  during  the  pre- 
paratory work  of  opening  a  deposit  and  also  during  the  ac- 
tual working  of  it,  the  foot  wall  and  the  roof  of  the  vein 
should  be  pierced  occasionally  to  discover,  if  possible,  min- 
eral deposits  that  may  lie  on  either  side  of  the  one  that  is 
worked  and  thus  to  secure  for  the  mine  a  long  and  prosper- 
ous future. 

One  good  result  of  this  will  be  the  furnishing  of  clear 
knowledge  concerning  the  extent  and  limits  of  the  metallife- 
rous mass,  the  extent  of  the  richer  ore,  and  the  various 
changes  which  they  exhibit.  In  these  respects  transverse 
galleries  do  good  service :  cross  clefts  and  fissures  are  also 
important  guides,  not  only  because  they  save  labor,  but  also 
because  frequently  they  are  either  themselves  metalliferous 
or  increase  the  richness  of  deposits  with  which  they  unite. 


FINAL  PREPARATIONS  AND  WORKING  OF  MINES.      277 

FINAL  PREPARATIONS  AND  WORKING  OF  MINES. 

The  opening  and  exploring  of  a  mine  are  succeeded  by  an- 
other preparatory  work,  namely,  the  division  of  the  mineral 
deposit  or  matter  into  smaller  portions,  and  both  these  labors 
find  their  termination  in  the  actual  working  or  "  stoping"  out 
the  ore.  This  final  work,  with  the  preparation  immediately 
preceding  it,  is  affected  very  much  by  the  bearing  and  in- 
clination and  by  the  thickness  and  regularity  of  the  vein  to 
be  mined.  Veins,  beds,  detached  masses,  etc.  require  differ- 
ent methods  of  working.  Still  there  are  some  general  prin- 
ciples common  to  all  the  different  methods.  The  deposits 
to  be  mined,  viewed  as  general  masses,  are  generally  divided 
into  smaller  portions  by  means  of  levels,  drifts,  intermediate 
drifts,  etc.,  and  by  shafts  and  wings,  and  thus  the  masses  are 
prepared  for  the  more  complete  extraction  of  their  most 
valuable  material.  When  a  mine  is  thus  prepared  the  ore 
is  then  said  to  be  "  exposed"  The  different  levels  and  drifts 
and  also  the  wings  ought  to  be  at  uniform  distances  from 
each  other  in  order  not  only  that  the  mine  may  present  the 
appearance  of  regularity,  but  also  because  this  method  aids 
greatly  in  taking  out  the  ore  with  regularity  and  order,  and 
it  renders  superintendence  and  oversight  much  easier. 

Systematic  mining  requires  a  thoughtful  consideration  of 
a  variety  of  matters.  And,  first  of  all,  there  ought  to  be  estab- 
lished a  correct  relation  between  the  preparatory  work  and 
the  extracting  of  the  ore,  that  is,  for  every  three  or  four 
miners  engaged  in  extracting  ore  that  has  been  exposed  to 
view  by  previous  preparatory  work,  there  ought  to  be  one 


278  MINERALS,   MINES,    AND   MINING. 

miner  engaged  in  this  preparatory  or  prospective  work,  so 
that  the  final  work  may  not  follow  right  on  the  heels  of  the 
preparatory,  or,  which  would  be  still  worse,  go  on  without 
any  such  preparatory  work. 

Again,  mining  to  be  conducted  judiciously  requires  that 
all  the  exposed  ore  be  not  hewn  out  as  soon  as  exposed, 
but  a  part  of  it,  especially  that  in  the  higher  levels,  be 
held  as  reserve  in  order  to  provide  against  a  time  of  need, 
and  also  that  an  average  may  be  brought  about  between 
higher  and  lower,  richer  and  poorer  ores,  which  is  the  more 
necessary,  since  the  lower  we  go  the  greater  the  difficulty 
and  cost  of  mining  and  the  poorer  or  less  abundant  are  the 
ores.  Judicious  mining,  therefore,  does  not  allow  the  ava- 
ricious taking  out  of  ores  which  are  rich  and  easily  accessible 
while  the  poorer  ores,  or  those  most  difficult  to  mine,  are  left 
neglected,  but  it  seeks  to  gain  the  rich  with  the  poor,  and, 
as  far  as  possible,  to  save  all  that  is  valuable. 

A  mine  which  is  worked  without  care  for  the  future  and 
without  regard  for  a  judicious  management  of  reserves  de- 
generates into  what  the  Germans  call  a  "robbing  of  the 
mine."  The  consequences  of  such  a  course  are  easily  pre- 
dicted: the  inferior  ores  that  remain  do  not  justify  the  ex- 
pense of  properly  opening  and  fitting  up  the  mine,  and 
sometimes  not  even  the  expense  of  extracting  them,  and  the 
owners  must  either  give  up  some  of  their  former  profits  or 
give  up  the  mine  and  leave  a  large  mass  of  useful  mineral 
unextracted. 

On  the  other  hand,  it  is  equally  important  to  gain  the  ore 
in  a  mine  as  easily  and  cheaply  as  possible.  To  secure  this 


VEINS   AND   LODES.  279 

it  is  necessary  to  adopt  some  system  with  reference  to  the 
work  and  also  with  reference  to  the  hands  employed.  As  a 
general  rule  a  stronger  force  is  put  to  work  in  the  lower 
levels  than  in  the  higher,  so  that  the  lowest  part  of  the 
mine  may  be  soonest  exhausted  and  the  cost  of  keeping  out 
the  water  and  bringing  the  products  to  the  surface  lessened. 

It  is  also  a  good  rule  not  to  scatter  the  working  force  over 
too  wide  a  space,  but  keep  them  in  a  limited  field,  and  when 
that  is  finished  let  it  be  left  forever.  In  this  way  a  good 
deal  is  saved  in  oversight  which  is  generally  very  expensive, 
and  more  is  saved  in  not  having  to  keep  open  and  in  repair 
long  galleries,  gangways,  or  deep  shafts,  which  would  require 
expensive  carpentry  or  masonry. 

As  to  the  number  of  miners  to  be  employed,  it  is  always 
better  to  have  too  few  than  too  many,  lest  they  should  be  in 
each  other's  way. 

Finally,  suitable  provision  must  be  made  for  a  thorough 
draining  or  ventilation  of  the  mine,  for  short  and  cheap 
transportation,  and  for  the  security  of  the  mine  and  the  lives 
of  the  miners,  guarding  them  against  being  buried  alive  by 
the  caving  in  of  any  portion  of  the  mine,  or  being  burned  to 
death  by  carelessness  or  insufficiency  of  protection  in  other 
respects. 

VEINS  AND  LODES.     How  PREPARED  AND  MINED. 

After  the  work  of  opening  and  exploring  has  sufficiently 
advanced,  some  further  arrangements  have  to  be  made  to 
mine  the  ore  to  the  best  advantage. 

If  the  vein  be  not  over  twelve  feet  thick,  and  preparations 


280  MINERALS,   MINES,   AND   MINING. 

are  to  be  made  for  mining  overhead,  then  the  method  will 
be  as  follows :  From  the  main  gangway  or  tunnel,  A  B,  Fig. 
33,  we  pierce  shafts  120,  130,  or  240  feet  apart,  as  CD, 
EF,  Fig.  33;  these  shafts  follow  the  inclination  of  the  vein, 
and  are  made  60  or  70  feet  upward.  From  these  shafts  we 
pierce  drifts,  G  H,  IK,  and  also  shorter  intermediate  drifts, 
LM,  NO.  In  this  manner  we  proceed  until  the  next  adit 
or  level  is  reached.  In  this  way  the  shafts  are  connected, 
the  vein  is  explored,  the  ore  is  exposed,  and  ventilation  and 
transportation  provided. 

Whilst  these  preparations  are  made  overhead,  similar  work 
is  done  below  the  floor  of  the  main  gangway.  Thus,  from 
the  gangway  AB,  Fig.  34,  a  shaft  CD  is  sunk  either  in- 
clined and  following  the  dip  of  the  vein,  or  perpendicular  in 
the  hanging  rock ;  in  the  latter  case  cross-tunnels  are  driven 
from  the  shaft  until  they  meet  the  vein.  From  those  points, 
or  at  suitable  distances  in  the  incline  shaft,  drifts  are  cut 
along  the  bearing  of  the  vein,  as  E  F,  0  H;  then  from  the 
lower  drift  to  the  upper  one,  shafts  are  pierced,  as  /  K,  L  M, 
NO,  with  or  without  short  intermediate  drifts,  P  Q,  R  S, 
and  thus  the  ore  is  reached.  If,  during  the  work  of  opening 
the  vein  as  described  in  the  sections  on  the  opening  of  mines, 
the  extent  of  the  pay-ore  has  become  known,  then  the  shafts 
are  arranged  in  such  a  manner  that  the  whole  mass  to  be 
mined  may  be  divided  into  equal  portions,  or  the  first  shaft, 
opened  as  CD,  Fig.  33,  is  placed  in  the  centre  of  the  field 
and  the  other  shafts  at  regular  distances  on  each  side. 

As  soon  as  this  preparatory  work  has  sufficiently  advanced 
the  final  work  of  exhausting  the  mine  is  commenced.     There 


VEINS   AND   LODES.  281 

are  two  ways  of  doing  this,  either  by  attacking  the  ore  over- 
head, or  by  attacking  the  ore  under  foot.  The  former 
method  is  especially  adapted  for  steep  veins;  the  latter  method 
is  suitable  for  either  steep  or  flat  deposits. 

Mining  overhead,  or  by  reverse  or  ascending  steps,  as  it  is 
sometimes  called,  may  be  conducted  in  two  ways.  The  first 
consists  of  leaving  a  strip  M^  Fig.  35,  of  vein  matter  which 
serves  as  a  floor  for  the  miners  to  stand  on  and  for  holding 
the  rubbish.  A  more  minute  description  would  be  as  follows: 
Let  A  B,  Fig.  35,  represent  the  main  gangway ;  G  Fis  a  shaft 
from  which  the  work  is  to  commence ;  at  the  point  C  are 
placed  two  miners  upon  a  platform,  who  commence  excavat- 
ing drifts  six  feet  in  height,  the  one  towards  D,  the  other 
towards  E.  They  do  not  commence  immediately  over  the 
roof  of  the  main  gangway,  but  leave  a  strip  M,  of  from  3 
to  6  feet  in  thickness,  which  serves  as  a  floor  for  the  drift 
they  are  excavating.  As  soon  as  these  drifts  have  advanced 
2  or  3  fathoms  the  drifts  marked  2  are  commenced,  then  3, 
and  so  on  until  the  next  gangway  is  reached,  where  again  a 
strip  similar  to  M  is  left  and  the  work  proceeds  as  before. 

From  the  material  that  is  there  hewn  out  the  ore  is 
selected  and  the  barren  rocks  are  used  for  filling  up  the 
empty  space,  or  for  supporting  the  overhanging  material. 
The  miner  stands  upon  this  rubbish,  and  in  order  that  the 
smaller  pieces  of  rich  ore  may  not  be  lost  among  the  rubbish 
a  floor  has  to  be  prepared  by  from  time  to  time  filling  in 
smaller  pieces. 

In  order  that  the  ore  obtained  may  be  more  easily  taken  to 
the  surface  by  means  of  the  main  gangway  there  are  pierced 


282  MINERALS,   MINES,   AND   MINING. 

through  the  strip  M,  in  distances  20  or  30  fathoms  apart, 
pitfalls  R,  S,  Fig.  36,  kept  open  by  timber  casings  as  far  as 
the  rubbish  accumulates.  In  the  same  manner  the  shaft  F 
G,  Fig.  36,  is  treated  unless  indeed  it  be  deemed  expedient 
to  wall  it  up  with  rock  and  use  it  as  a  transporting  shaft. 

The  method  just  described,  i.  e.,  the  leaving  of  a  strip  in- 
stead of  making  a  strong  frame  by  timbering,  is  not  always  to 
be  recommended.  For  in  view  of  little  thickness  the  timbering 
does  not  cost  a  great  deal,  therefore  there  is  no  great  saving ; 
and  in  view  of  great  thickness  these  strips  are  dangerous 
unless  they  are  taken  very  thick,  which  would  involve  the  loss 
of  a  large  quantity  of  ore,  for  it  is  generally  deemed  essential 
to  take  the  strip  three  or  four  times  the  thickness  of  the  vein. 
It  is  only  where  these  veins  are  to  be  worked,  and  where  at 
the  same  time  the  gangue  is  both  easily  mined  and  firm,  and 
where  wood  is  scarce  that  this  method  would  be  advantage- 
ous. 

The  other  method  of  working  overhead  is  as  follows :  The 
roof  of  the  gangway  or  tunnel,  in  Fig.  37,  is  used  as  the  floor 
of  the  first  drift,  and  for  this  purpose  it  is  prepared  with  heavy 
timber  or  stone  arch,  K,  of  sufficient  strength  to  support  the 
rubbish  V.  Thus,  as  the  drift  marked  1,  in  Fig.  37,  advances 
from  C,  the  timbering  or  walled  arch  follows  it.  If  the  rub- 
bish rises  too  high  or  becomes  too  heavy,  additional  supports, 
as  K,  have  to  be  provided  in  order  that  the  entire  weight 
may  not  be  held  up  by  one  set  of  timbers,  as  at  K,  but  bs 
distributed  over  several  as  at  JT,  /f ,  etc.  The  side  of  the  shaft 
taken  away  is  replaced  by  timber  casings,  as  at  C  Z,  or  a 
wall  is  made  of  the  larger  pieces  of  barren  rock. 


PLATE  VI 


FIG.  35. 


FIG.  36. 


FIG.  37. 


FIG.  38. 


To  face  page  282. 


.SE  ue^ 

(<  <*'«fll^ 


VEINS   AND    LODES.  283 

Every  10,  20,  or  30  fathoms'  distance  apart  holes  are  left 
in  the  roof  7tT,  for  the  purpose  of  throwing  down  the  ore  as 
it  is  hewn  out.  Large  pieces  of  very  rich  ore  are  handed 
down  in  sacks  or  baskets  to  prevent  loss  from  the  rougher 
mode  of  handling. 

The  method  of  working  downwards  is  simply  the  reverse 
of  that  just  described.  In  Fig.  38,  let  A  B  represent  a  main 
level  or  gangway;  CD  is  a  shaft  sunk  along  the  slope  of  the 
vein.  At  the  point  C  a  miner  begins  to  excavate  the  drift 
1.  When  he  has  proceeded  a  few  fathoms  another  miner 
commences  drift  2  and  so  on.  In  this  way  the  working 
presents  the  appearance  of  descending  stairs.  As  in  the  case 
of  the  overhead  working,  so  here  the  work  may  be  carried 
on  on  two  sides  simultaneously.  In  this  method  the  miners 
stand  not  on  the  rubbish,  but  on  the  ore.  The  ore  hewn  out 
in  this  manner  is  hoisted  up  by  means  of  a  windlass  or  in  some 
other  way  through  openings  left  in  the  floor  of  the  tunnel, 
and  the  rubbish  is  thrown  on  timber  casings,  JT,  which  are 
formed  between  each  two  drifts  and  laid  securely  with  heavy 
timbers. 

Since  the  floor  of  the  tunnel  A  B  and  the  side  of  the  shaft 
CD,  Fig.  38,  are  hewn  away  by  the  first  drift,  their  places 
have  to  be  supplied  by  timbers  Z. 

In  coal-mines  this  method  of  working  by  descending  steps 
has  been  abandoned,  because  where  the  miners  stand  upon 
the  coal  they  crush  the  coal;  moreover,  ventilation  is  more 
difficult  and  a  great  deal  of  timber  is  required. 

In  both  these  methods  of  mining,  i.  e.,  descending  steps 
and  reversed  steps,  the  ore  presents  two  exposed  sides,  one 


284  MINERALS,   MINES,   AND   MINING. 

in  front  and  the  other  either  above  or  below ;  sometimes  the 
miner  forms  a  third.  For,  if  the  vein  has  a  selvage  or  par- 
tition rock,  easily  worked  and  of  little  or  no  value,  the 
miner  hews  a  trench  into  this  and  thus  frees  it  from  the  side 
rock  and  then  drills  holes  for  blasting  or  wedging  in  the  ore 
mass.  But  if  the  vein  be  firmly  attached  on  both  sides  to 
the  rock  the  advantage  of  having  the  ore  exposed  on  three 
sides  cannot  be  had  unless  a  trench  be  made  in  the  ore  itself, 
which,  however,  ought  not  to  be  done  if  the  ore  be  pure  or 
rich,  nor  ought  holes  for  blasting  to  be  drilled  into  such  ore. 
It  is  better  to  free  the  ore-mass  by  cutting  a  groove  or  incis- 
ion, and  then  with  pick  or  hammer  and  chisel,  or  a  very 
weak  blast,  the  ore  is  obtained.  Each  method  of  working, 
i.  e.,  by  descending  steps  or  reversed  steps,  has  its  advan- 
tages and  disadvantages. 

In  working  by  reversed  steps  the  miner  has  to  work  over- 
head, which  is  inconvenient,  but  then  the  weight  of  the  rock 
assists  him,  because  it  is  more  easily  detached  from  above 
downward  than  in  the  reverse  direction.  Moreover,  less 
timber  is  required  and  the  labor  of  transporting  the  ore  out 
of  the  mine  is  lessened.  Still  there  is  considerable  loss,  be- 
cause some  of  the  ore  will  roll  among  the  rubbish  on  which 
the  miner  has  to  stand. 

In  the  other  method,  i.  e.,  by  descending  steps,  the  work 
is  easier,  for  the  miner  works  in  a  more  convenient  posture 
and  can  use  water  in  drilling ;  there  is  also  less  loss  of  ore, 
because  there  is  a  solid  floor  to  stand  upon.  But  then  more 
timber  is  required;  the  cost  of  transporting  the  ore  out  of 
the  mine  is  greater,  because  it  has  to  be  hoisted  by  means  of 


VEINS   AND   LODES.  285 

a  windlass  up  to  the  main  gallery;  and  then  in  mines  where 
water  abounds  it  is  difficult  to  drain  the  workings  properly 
so  as  not  to  inconvenience  the  miners. 

All  things  considered,  the  method  of  working  overhead 
or  by  reversed  steps  is  the  preferable  one  and  is  the  one  gen- 
erally adopted. 

When  a  vein  or  lode  is  not  uniformly  rich,  when  the  ore 
is  deposited  in  small  detached  masses  or  in  pockets  or  nests, 
then  the  method  of  working  is  as  follows :  By  means  of 
short  tunnels  the  ore  is  sought,  and  when  discovered  it  is 
extracted  by  piercing  shafts  or  wings  which  follow  the  ore 
and  determine  the  extent  of  the  pockets  and  then  all  that 
is  worth  mining  is  taken  out.  (See  Fig.  39.)  Of  course 
entire  regularity  in  such  workings  is  out  of  the  question, 
still  there  ought  to  be  some  regularity  in  the  direction  of  the 
drifts  and  the  distance  between  them ;  care  must  also  be 
taken  to  secure  ventilation  and  provide  for  the  safety  of  the 
miners. 

Lodes  of  more  than  two  or  three  fathoms'  thickness  are 
worked  by  what  is  called  a  cross-work.  The  lode  is  pre- 
pared for  working  by  making  gangways  or  drivings  at  A  B, 
either  in  the  hanging  or  lying  wall,  as  in  the  plan,  Fig.  40, 
which  gangways  are  used  for  transporting  the  ore  and  are 
heavily  timbered.  When  these  preparations  are  finished 
cross-cuts  or  breasts,  1,  2,  3,  etc.,  are  marked  off.  These 
cross-cuts  are  made  from  one  to  two  fathoms  in  width  and 
one  fathom  in  height,  and  cut  at  right  angles  to  the  gang- 
way A  B  until  they  reach  the  opposite  wall,  C.  These 
breasts  are  worked  in  such  a  way  that  beside  each  one  that 


286  MINERALS,   MINES,    AND   MINING. 

is  worked,  1,  2,  3,  or  more  will  remain.  For  example,  first 
the  breasts  1,  3,  and  5  are  opened  and  then  2  and  4 ;  or 
first  1  and  5,  then  2  and  4,  and  finally  3,  which  has  re- 
mained as  a  support  for  the  roof.  The  breast  5  is  then  taken 
as  the  first  of  the  next  division  and  so  on. 

While  these  breasts  are  worked  they  are  furnished  with 
timber  casings  if  necessary,  the  rubbish  is  put  at  the  side  of 
the  breast,  and  the  ore  taken  out  into  the  gangway  A,  Fig. 
41. 

When  a  breast  reaches  the  wall  the  timbers,  with  the  ex- 
ception of  those  on  the  floor,  are  taken  out  and  the  whole 
breast  is  completely  filled  up  with  rubbish.  Where  no  tim- 
bers have  been  used  during  the  progress  of  cutting  the  breast 
the  floor  must  be  covered  before  it  is  filled  up  and  abandoned, 
lest  at  some  future  time,  when  coming  up  from  a  lower  level, 
these  barren  rocks  endanger  the  workings. 

o  o 

Before  all  the  breasts  which  open  on  the  level  A,  Fig.  41, 
and  which  together  constitute  one  story,  are  attacked,  steps 
are  taken  to  open  a  second  story,  H,  immediately  over  the 
first,  T.  For  this  purpose  a  gangway,  A,  is  made  over  A, 
so  that  the  roof  of  A  shall  be  the  floor  of  A.  This  is  also 
furnished  with  timber  casings,  but  openings  are  left  in  the 
floor  ten  fathoms  apart  through  which  the  ore  is  cast  into 
the  gangway  A.  From  the  gangway  A  cross-cuts  or  breasts 
are  driven  through  the  entire  thickness  of  the  vein.  After 
the  work  has  advanced  to  a  certain  extent  on  this  story  a 
third  story  is  opened  and  then  a  fourth,  and  so  on.  But  it 
must  be  observed  that  two  breasts,  the  one  of  which  is  di- 
rectly over  the  other,  ought  never  to  be  worked  at  the  same 


FIG.  40. 


\         2 3 


Fro.  42. 


PLATE  VII. 

FIG.  39. 


FIG.  41. 


To  face  page  286. 


STRATIFIED    DEPOSITS   AND    BEDS.  287 

time,  but  the  breasts  worked  in  the  upper  stories  must  al- 
ways be  over  breasts  not  yet  cut  out  or  over  breasts  rilled  up 
with  barren  rock.  The  working  of  the  cross-breasts  is 
therefore  arranged  in  such  a  way  that  by  the  side  of  each 
one  that  is  actually  worked  there  shall  be  as  many  left  as 
there  are  stories  or  tiers.  (See  Fig.  42.)  The  work  is  then 
prosecuted  after  the  manner  of  working  by  reversed  steps 
described  in  pages  281  and  282.  Commonly  not  more  than 
ten  tiers  or  stories  are  taken  to  constitute  a  working  field ; 
the  eleventh  story  has  its  tunnel  fitted  up  so  as  to  be  used 
as  a  main  or  transporting  gallery. 

When  a  large  mass  of  barren  rock  is  met  in  working  a 
deposit  at  T7,  Fig.  43,  it  is  left  standing  and  the  ore  behind 
it  or  above  or  below  is  obtained  by  mining  around  the  ob- 
stacle. It  is  sometimes  the  case,  however,  that  what  appears 
to  be  a  barren  mass  may  contain  within  it  a  valuable  ore ; 
it  is  not  well,  therefore,  to  leave  such  a  mass  hastily,  but 
rather  pierce  through  it  at  some  point. 

PREPARATION  AND  WORKING  OF  STRATIFIED  DEPOSITS 
AND  BEDS. 

The  working  of  layers  or  beds  of  great  inclination  corre- 
sponds, in  the  main,  with  that  of  lodes  or  veins.  But  beds 
whose  inclination  is  less  than  40  degrees  are  worked  in  one 
of  two  ways,  by  the  long  wall  system,  or  post  and  stall 
workings. 

The  former  method  is  adapted  to  thin  and  nearly  hori- 
zontal beds,  which  furnish  a  sufficient  amount  of  rubbish. 
This  method  is  really  very  similar  to  that  described  on 


288  MINERALS,   MINES,   AND   MINING. 

pages  281,  282,  and  is  conducted  very  much  in  the  same 
way,  only  that  the  workings  which  in  that  case  had  a  per- 
pendicular direction  are  carried  on  here  in  a  horizontal  one. 

The  following  is  a  more  detailed  description  of  this 
method  of  working.  The  bed  or  deposit  to  be  worked  is 
prepared  by  opening  on  a  certain  level  a  tunnel  A  J5,  Figs. 
44  to  47.  This  tunnel  is  made  of  sufficient  height  to  be 
used  as  a  transporting  gallery.  If  this  tunnel  is  also  the 
lowest  of  the  mine,  it  is  called  the  ground  level  or  dip  head 
level.  The  portion  of  the  bed  or  layer  above  this  ground 
level  is  further  prepared  by  opening  parallel  levels  C  C,  and 
diagonal  drifts  Z>,  Fig.  44,  or  by  drifts  perpendicular  to  the 
ground  level,  as  E  E  in  Fig.  45.  If  the  inclination  of  the 
strata  or  "vein"  be  insufficient  to  admit  of  rolling  down  the 
material  hewn  out,  and  at  the  same  time  too  steep  to  admit 
of  transportation  with  carts  or  barrows,  then  the  mine  is  pre- 
pared by  diagonal  drifts  F  F,  as  in  Fig.  46.  Thus  in  one 
or  the  other  of  these  ways  the  bed  is  divided  into  portions 
1,  2,  3,  etc.,  each  of  which  is  from  25  to  50  fathoms  long  in 
the  direction  of  the  strike  or  bearing,  and  from  10  to  30 
fathoms  in  the  direction  of  the  dip.  The  field  thus  pre- 
pared is  generally  bounded  on  the  upper  side  by  a  level  G  H, 
Figs.  44,  45,  46,  which  is  used  as  the  ground  level  in  work- 
ing the  next  field,  or  which  has  already  been  so  used.  To 
secure  ventilation  the  levels  or  drifts  are  united  by  crosscuts, 
as  at  /  in  Figs.  44  and  45. 

Each  breast  or  working  face  in  its  entire  width  is 
occupied  by  miners  who  work  one  above  the  other  in  such  a 


PLATE  VIII. 

FIG.  43. 


FIG.  44. 


P/tm. 


FIG.  45. 


FIG.  46. 


FIG.  47. 


c 


To  face  page  288. 


STRATIFIED   DEPOSITS   AND   BEDS.  289 

way  that  the  steps  or  tiers,  Nos.  2,  3,  etc.,  recede  like  stair- 
steps with  reference  to  the  breast  No.  1,  see  Figs.  44  and  45. 

Whilst  the  work  is  thus  going  forward  the  roof  in  the 
excavated  space  is  temporarily  supported  by  timbers  until 
it  can  be  more  permanently  filled  up.  Care  must  be  taken 
to  leave  open  and  unobstructed  the  levels  and  diagonal  drift 
along  which  the  mineral  is  transported  to  the  ground  level 
A  B  or  the  shaft  S.  (See  Figs.  44,  45,  and  46.) 

With  the  exception  of  thin  and  slightly  inclined  coal-beds, 
this  method  is  used  only  in  the  cupriferous  slate  strata  of 
Mansfeld. 

The  post  and  stall  method  is  used  in  deposits  and  beds  of 
considerable  thickness  which  do  not  furnish  a  sufficient 
amount  of  rubbish,  and  where  pillars  must  be  left  to  support 
the  roof,  or  where  the  roof  is  allowed  to  crush  down. 

The  preparatory  work  for  this  method  of  mining  is  as 
follows : — 

At  the  lowest  level  of  the  bed,  a  tunnel  or  ground-level 
A  B,  Figs.  47  and  48,  is  made  which  may  be  two  fathoms  in 
width.  Perpendicular  (?'.  e.,  right-angled)  or  diagonal  to 
this  a  drift  C  is  made,  and  crossing  this  at  regular  intervals 
of  two  or  three  fathoms  levels  D  D  parallel  into  the  ground- 
level  A  B.  In  this  manner  the  bed  or  deposit  is  divided 
into  long  strips.  These  are  again  cut  through  at  intervals 
of  from  three  to  six  fathoms  by  drifts  perpendicular  or  right- 
angled  to  the  ground  level,  and  thus  the  necessary  arrange- 
ments for  transportation  and  ventilation  are  made  and  the 
rectangular  (horizontally  long)  or  square  (vertically  short) 
pillars.  See  (P)  Figs.  47  and  48.  The  size  of  these  pillars 

19 


290  MINERALS,   MINES,   AND  MINING. 

depends  upon  the  nature  of  the  roof  and  the  solidity  of  the 
floor. 

The  taking  out  of  the  pillars  begins  when  the  levels,  or 
drifts,  have  reached  the  end  of  the  bed,  or  the  extent  of  the 
field  to  be  worked,  or  exhausted  portions  of  the  mine,  or  in 
general  arrived  at  the  predetermined  limits.  The  beginning 
is  made  at  the  point  farthest  removed  from  the  main  or  work- 
ing shaft  or  gangway  and  the  work  proceeds  towards  this 
shaft  or  gangway  so  that  the  roof  may  be  allowed  to  crush  in 
without  interfering  with  transportation  and  ventilation  and 
the  workings  still  be  carried  on  in  other  portions  of  the  mine. 

The  separate  pillars  are  taken  one  after  another,  beginning 
with  the  upper  one  and  proceeding  down  in  the  direction  of 
the  dip.  Before  this  is  commenced  and  while  it  is  going  on, 
the  roof  has  to  be  supported  either  by  timbers  or  dry  walls. 
As  soon  as  one  pillar  has  been  taken  away  and  the  materials 
composing  it  removed,  the  timbers  supporting  the  roof  are 
carefully  taken  away,  provided  it  can  be  done  without  dan- 
ger, otherwise  they  are  abandoned  and  the  roof  is  allowed  to 
fall. 

If  the  roof  is  very  brittle,  it  is  sometimes  best  to  leave  some 
of  the  pillars  standing,  or  to  build  hollow  pillars  of  rock 
which  are  filled  with  coal  waste,  which,  in  order  to  guard 
them  against  spontaneous  combustion,  are  kept  from  the 
draft  of  air. 

In  coal-beds,  levels  and  drifts  are  cut  most  advantageously 
in  the  following  manner :  The  miner  cuts  with  his  pick  in 
the  most  suitable  place,  generally  as  near  the  floor  as  possi- 
ble, a  shallow  horizontal  groove  S,  Fig.  49,  as  deep  into  the 


FIG.  48. 


PLATE  IX. 


FIG.  49. 


FIG.  50. 


FIG.  51. 


To  face  page  290. 


STRATIFIED   DEPOSITS   AND   BEDS.  291 

coal  as  possible.  The  coal  thus  liberated  is  supported  by 
blocks,  H,  and  props  T.  Then  perpendicular  grooves  are 
cut  through  the  entire  thickness  of  the  bed  and  as  deep  as 
the  groove  8.  In  this  way  blocks  are  formed  which  are  free 
on  four  sides  and  which  may  easily  be  detached. 

In  coal-beds  composed  of  several  different  layers  or 
"  benches"  of  different  degrees  of  hardness,'  the  first  or  hori- 
zontal groove  is  made  in  the  softest  layer,  but  in  beds  of  greater 
thickness  generally  in  the  middle  (Fig.  50),  in  which  case  the 
upper  portion  is  removed  first.  In  beds  of  very  great  thick- 
ness the  galleries  are  not  cut  through  the  entire  thickness  at 
once,  but  in  successive  layers  or  tiers.  (See  Fig.  51.) 

If  the  roof  or  walls  need  support,  this  is  supplied  as  the 
excavation  of  the  level  or  drift  proceeds.  This  support  con- 
sists generally  of  posts  which  are  let  into  the  floor  and  wedged 
firmly  and  perpendicularly  against  the  roof. 

In  coal  mines  spontaneous  combustion  not  unfrequently 
occurs,  especially  where  a  part  of  the  roof  is  allowed  to  crush 
in.  It  is  generally  supposed  that  the  cause  is  to  be  found  in 
the  decomposition  of  pyrites  (iron  sulphide)  contained  in  the 
remaining  coal  and  the  contiguous  clay-slate.  Frequently 
such  combustions  result  in  extensive  conflagrations.  The 
most  effective  mode  of  prevention  of  such  calamities  would  be 
to  fill  up  the  excavated  spaces  completely  before  they  are  aban- 
doned and  before  the  roof  is  allowed  to  crush  in.  But,  inas- 
much as  this  would  involve  too  great  an  expense,  the  next 
best  means  ought  to  be  resorted  to,  which  would  be  to  sepa- 
rate and  shut  off  any  extended  portion  of  the  mine,  that  has 
been  abandoned,  from  that  which  is  still  worked,  by  walls 


292  MINERALS,   MINES,    AND   MINING. 

of  stone  and  dams  of  clay,  etc.     Only  in  case   of  absolute 
necessity  is  it  allowable  to  inundate  the  workings. 

The  precautionary  rules  are,  not  to  expose  the  coal  to  a 
stronger  current  of  air  than  is  absolutely  necessary  for  pur- 
poses of  ventilation  ;  and  not  to  prepare  too  extensive  a  field 
at  one  time;  to  leave  pillars  of  sufficient  strength  to  prevent 
a  premature  caving  in ;  and  to  begin  the  work  of  taking  out 
the  pillars  and  abandoning  the  field  as  soon  as  the  previous 
work  is  .completed. 

PREPARATION  AND  WORKING  OF  MINERAL  DEPOSITS  THAT 
OCCUR  IN  LARGE  MASSES. 

In  mining  deposits  of  irregular  form,  and  containing  large 
masses,  the  form  and  extent  of  them,  and  the  nature  of  the 
surrounding  rock  will  determine  the  method  to  be  pursued. 
Large  deposits  which  possess  some  degree  of  regularity  may 
generally  be  mined  by  what  has  already  been  described  as 
the  cross  system  of  mining.  Deposits  with  little  or  no 
regularity  of  form  require  a  peculiar  method.  As  a  general 
rule  the  aim  should  be  to  find  the  extent  of  the  deposit  in 
a  downward  direction  and  then  work  from  below  upwards, 
as  this  will  be  found  easier  and  more  profitable. 

The  manner  of  preparing  such  a  deposit  is  about  as 
follows : — 

When  the  deposit  has  been  discovered  by  means  of  an 
adit  or  tunnel  and  this  tunnel  has  entered  the  ore,  then 
shafts  are  pierced  both  above  and  below  either  perpendicular 
or  inclined,  and  from  these  shafts,  at  moderate  intervals, 
drifts . are  run  in  the  ore-mass,  as  A  B  C,  Fig.  52.  If  the 


PLATE  X. 


FIG.  52. 


FIG.  54. 


FIG.  53. 


To  face  page  292. 


MINERAL   DEPOSITS   IN   LARGE   MASSES.  293 

deposit  has  been  discovered  by  a  shaft,  a  cross  gallery  is 
run  and  from  this  the  work  proceeds  as  above.  Along  these 
drifts  vault-like  chambers  are  formed  by  hewing  away  from 
the  sides,  roof,  and  floor,  which  are  enlarged  as  far  as  the 
solidity  of  the  ore-mass  will  permit.  Between  each  two 
vaults  lying  above  each  other,  ore  of  sufficient  thickness  is 
left  to  serve  as  a  floor  for  the  upper  one,  also  pillars,  and 
both  floors  and  pillars  as  much  as  possible  of  worthless  ore. 
The  pillars  ought  to  be  so  arranged  that  they  will  be  over 
each  other,  and  a  sufficient  amount  of  ore  should  be  left 
around  the  shaft  to  prevent  their  caving  in.  The  floors  are 
pierced  wherever  it  is  necessary  in  order  to  transport  ore 
either  up  or  down. 

The  miners  while  at  work  stand  upon  the  accumulated 
rubbish  or  upon  ladders  or  scaffolds. 

If  one  of  the  vaults  should  become  too  large  and  be  in 
danger  of  crushing  in,  or  if  the  ore-mass  is  composed  of 
hanging  and  lying  ore- veins,  then  it  is  best  to  run  drifts  in 
different  directions  which  start  from  the  same  point  or  cross 
each  other.  When  these  drifts  reach  the  limits  of  the  ore, 
new  vaults  are  made.  In  this  manner  there  are  exposed 
irregular  masses  of  inferior  ore  which  may  be  worth  mining, 
but  are  difficult  to  extract  because  surrounded  by  large 
spaces.  In  order  to  gain  all  these  masses  those  between  two 
contiguous  drifts  are  divided  in  the  direction  of  the  drifts 
into  2,  3,  4,  etc.,  perpendicular  portions  (see  Fig,  53),  after 
which  the  floors,  pillars,  etc.  are  taken  out  in  regular  order, 
beginning  with  the  division  at  the  lowest  level  and  leaving 
what  is  worthless  whether  in  the  shape  of  pillar  or  floor. 


294  MINERALS,    MINES,   AND    MINING. 

The  rubbish  is  so  placed  that  it  may  support  the  roofs  which 
rest  upon  pillars  that  are  to  be  taken  down.  If  sufficient 
rubbish  for  this  purpose  is  wanting,  pillars  are  made  of  tim- 
ber filled  in  with  rubbish. 

If  in  spite  of  all  precautions  a  part  of  the  mine  should 
crush  in,  the  valuable  ore  contained  in  the  wreck  may  be 
gained  in  the  following  manner.  The  wreck  is  approached 
by  means  of  drifts  or  galleries  which  are  secured  with  tim- 
bers as  they  advance.  When  these  galleries  reach  valuable 
ore  it  is  taken  away  from  the  breast  of  the  gallery,  and  as 
it  is  taken  new  materials  are  allowed  to  roll  down  from 
above  as  long  as  they  continue  to  be  valuable.  When  they 
cease  to  be  so,  the  broken  mass  is  approached  from  another 
side.  This  kind  of  work  is  generally  reserved  for  miners 
who  wish  to  work  extra  time  and  are  willing  to  take  what 
they  can  make. 

This  method  described  in  the  preceding  paragraphs  finds 
its  application  also  in  rock-salt  works.  In  deposits  which 
contain  salt  in  large  and  almost  pure  masses  galleries  are 
cut,  as  shown  in  Fig.  54.  These  are  brought  into  communi- 
cation with  each  other  and  with  the  main  shaft.  These 
tunnels  are  then  enlarged  by  hewing  away  from  the  sides 
and  roofs  as  shown  in  Fig.  55.  The  dissolving  power  of 
water  is  made  use  of  in  such  works  with  great  advantage. 
The  water  is  conducted  into  pipes  which  have  a  row  of  fine 
holes  along  their  entire  length  through  which  the  water 
flows  in  fine  thread-like  streams  against  the  salt.  These 
threads  soon  cut  deep  grooves  in  the  salt  and  large  masses 
may  then  be  detached  at  once. 


PLATE  XI. 


FIG.  55. 


FIG.  56. 


FIG.  57. 


FIG.  58. 


FIG.  59. 


Mm, 


To  face  page  294. 


MINERAL   DEPOSITS   IN   LARGE   MASSES.  295 

The  method  of  gaining  the  salt  in  a  mine  by  dissolving  it 
is  almost  entirely  out  of  use.  The  particular  method  of 
running  the  gangways  and  communications  between  them 
vertically  and  the  rectangular  branches  conveying  the  water 
toward  the  opening  may  be  understood  sufficiently  by  ex- 
amining Figs.  55  and  56,  one  being  a  vertical  section,  the 
other  a  ground-plan. 

In  solid  rock,  as  for  instance  in  limestone,  quartz  rock  and 
the  like,  it  is  usual  to  have  recourse  to  the  work  of  rock 
blasting,  with  drill  and  powder  of  various  kinds.  In  the 
salt-bearing  slates,  and  material  of  similar  strength,  generally 
the  pick-axe  serves  sufficiently  well,  but  more  recently  and 
with  greater  advantage  and  perhaps  in  California  with  the 
greatest  possible  advantage,  the  water  stream  is  used,  which 
is  described  more  fully  on  p.  298,  "  Buddling."  In  some 
of  the  salt  mines,  as  stated  by  Niederist,  the  following  method 
is  used  in  progressing  against  a  breast  in  a  gangway :  The 
figures  explain  the  process  sufficiently  where  (Fig.  57)  A  A  is 
the  pipe  conveying  water  from  a  high  level,  and  of  conse- 
quent high  pressure.  B  is  the  stand-pipe  and  C  G  are  the 
nozzles  from  which  the  water  escapes  and  dashes  with  great 
force  against  the  soil  or  mineral;  Fig.  58  shows  the  bracing 
of  the  standpipe. 

Preparation  and  Working  of  Nests,  Cores,  or  Pockets. 

In  working  small  irregular  deposits,  such  as  nests,  cores, 
or  pockets  and  shoots  from  larger  veins,  we  have  to  be 
governed  by  their  size  and  form.  The  smaller  and  the 
more  irregular  they  are,  the  more  necessary  it  is  to  follow 


296  MINERALS,    MINES,   AND   MINING. 

closely  the  direction  of  the  ore  and  not  attempt  to  do  much 
in  the  way  of  prospecting.  If  they  assume  the  form  of  veins 
or  beds,  or  larger  masses,  they  are  worked  in  accordance 
with  the  conditions. 

In  working  cores  or  threads  the  sides  of  the  tunnel  should 
be  as  clean  and  smooth  as  possible,  because  these  cores  fre- 
quently send  out  branches  which  may  lead  to  the  discovery 
of  other  deposits,  if  scrutinized  carefully  when  free  from  rock 
and  other  misleading  substances. 

SURFACE  OR  DAY-WORKING. 

Surface  or  day-working  is  that  where  the  deposits  to 
be  worked  occur  at  a  moderate  depth  below  the  surface  and 
which  admit  of  the  covering  mass  being  removed.  To  this 
class  belong  deposits  of  peat  or  turf,  bog  iron  ore,  rock-salt, 
flat  coal-beds  and  even  deposits  of  ore.  The  work  includes 
stripping,  quarrying,  and  bundling. 

The  work  of  stripping  consists  in  removing  the  surface 
soil  and  thus  exposing  the  deposit.  The  mass  to  be  taken 
away  must  be  removed  to  one  side,  or  at  any  rate  to  a  place 
where  it  will  not  impede  the  subsequent  work,  and  where  at 
the  same  time  it  will  be  convenient  to  fill  up  excavated 
spaces  if  it  should  be  needed  for  that  purpose.  When  this 
is  done,  a  cut  is  made  to  the  bottom  of  the  deposit,  or  at  any 
rate  to  a  considerable  depth  where  a  ditch  is  made  to  convey 
away  the  water,  or  a  cistern  to  collect  the  same.  Then  the 
working  is  carried  on  by  descending  steps.  At  the  same  time 
care  has  to  be  taken  that  the  breast,  or  the  wall,  does  not 
cave  in  and  endanger  the  workmen. 


SURFACE   OR   DAY- WORKING.  297 

In  open  quarrying  there  may  be  gained  not  only  building 
stones,  mill-stones,  and  the  like,  but  also  valuable  minerals, 
as  rock-salt,  iron  ore,  etc. 

The  mass  to  be  mined  may  be  loose  or  solid.  In  the 
former  case  it  is  best  to  arrange  and  prosecute  the  working 
by  steps  or  cuts,  1,  2,  3,  etc.,  Fig.  59,  and  to  roll  down  the 
material  gained  from  the  upper  to  the  lower  steps,  and  to 
facilitate  this  an  inclined  plane  is  made  in  the  middle  of  the 
quarry  by  cutting  away  the  corners  of  the  steps ;  this  incline 
ought  to  be  about  45°. 

If  solid  rock  is  to  be  quarried,  then  the  method  will  depend 
upon  the  size  and  form  which  the  pieces  ought  to  have. 
Large  regular  building  stones  and  mill-stones  are  gained  by 
cutting  grooves  and  driving  in  wedges  along  the  line  of  the 
groove,  and  also  by  blasting.  Smaller,  irregular  pieces  are 
obtained  by  blasting,  and  most  easily  by  adopting  the  method 
of  descending  steps.  In  various  mines  or  quarries,  as  in 
Middletown,  Connecticut,  large  blocks  are  easily  opened  in 
almost  any  direction  by  driving  in  perfectly  dry  pins  into 
the  holes  prepared  during  the  day  along  the  line  of  the  de- 
sired opening,  and  just  before  the  workmen  are  dismissed 
water  is  poured  in  the  groove.  The  swelling  of  the  wood, 
by  morning,  opens  a  seam,  and  the  removal  of  the  block  is 
easily  effected.  In  case  the  holes  were  not  deep  enough  and 
the  pins  or  wedges  are  not  long  enough,  alternate  holes  are 
made  and  the  trial  repeated  the  next  night.  The  miner 
must  learn  this  process  and  judge  of  its  special  efficiency  by 
the  nature  of  the  rock ;  generally  in  sand-rock  holes  six 
and  eight  inches  deep,  one-and-a-quarter  inch  diameter,  are 


298  MINERALS,   MINES,   AND    MINING. 

quite  sufficient,  at  an  interval  for  each  hole  of  eight  or  nine 
inches.  In  some  brittle  and  soft  rocks  these  measurements  are 
greater  than  necessary. 

When  a  quarry  is  first  opened  it  is  necessary  to  remove 
the  covering  mass  to  a  place  where  it  will  not  be  in  the  way. 
It  is  also  necessary  to  provide  a  suitable  road,  so  that  the 
teams  can  drive  up  to  the  workings  and  prevent  unnecessary 
hauling,  or  moving  of  the  quarried  mass. 

To  avoid  the  removal  of  a  very  thick  covering,  and  to  be 
able  to  work  during  winter,  or  in  case  the  quarry  is  difficult 
of  access,  it  is  sometimes  well  to  work  it  under  ground  with 
tunnels.  Where  the  covering,  however,  extends  a  great  dis- 
tance, as  at  the  iron  mines  near  Hokendauqua,  Pennsylvania, 
and  other  places  in  this  region,  the  tunnels  must  be  driven 
from  shafts.  In  this  plan  the  enormous  deposits  of  water  in 
the  workings  would  be  avoided,  but  where  wood  is  dear  and 
hard  to  be  had  the  necessary  timbering  must  be  considered 
as  an  objection.  The  cost  of  hoisting  engines,  fuel,  etc.,  would 
be  about  the  same  in  either  case. 

Buddling  is  the  method  of  gaining  useful  minerals  by 
means  of  water  and  the  specific  gravity  of  the  minerals. 
There  is  a  great  variety  of  methods  more  or  less  complicated. 
One  of  the  simplest  methods  is  that  employed  in  steep  moun- 
tain valleys,  where  a  ditch  is  dug,  beginning  at  the  lowest 
point  and  casting  the  mass  to  be  washed  in  at  the  top  and 
causing  water  to  wash  it  down.  In  this  way  the  coarse  and 
worthless  particles  will  be  found  on  top,  lower  down  the 
finer  sand,  and  the  finest  with  the  valuable  mineral  at  the 
bottom.  The  worthless  is  cast  awav,  the  next  grade  is 


SURFACE   OR   DAY-WORKING.  299 

crushed  if  necessary,  and  with  the  finest  is  washed  ag%ain  in 
suitable  apparatus. 

Instead  of  ditches  various  mechanical  contrivances  are 
used,  such  as  the  washboard,  which  is  especially  adapted  for 
minerals  found  in  coarse  grains,  as  gold.  It  is  three  or  four 
feet  in  length  and  has  shallow  grooves  running  crosswise, 
and  is  at  the  sides  supplied  with  a  rim.  This  washboard  is 
placed  in  a  ditch  having  a  slight  inclination ;  the  earth  to  be 
washed  is  put  into  the  ditch  above,  and,  with  constant  stirring, 
is  washed  first  on  the  board  and  then  over  the  same.  When 
a  certain  amount  has  been  washed,  the  board  is  lifted  out; 
and  the  sand  collected  in  the  grooves  is  emptied  into  a  vessel 
and  the  metal  is  separated.  Several  such  boards  are  gene- 
rally placed  at  distances  of  one  or  two  fathoms  apart,  and  at 
the  end  of  the  ditch  a  dam  is  erected  to  intercept  the  sand 
so  that  it  can  be  washed  again. 

If  the  mineral  particles  are  very  fine,  the  muddy  water  is 
conveyed  over  a  series  of  sieves,  and  thus  the  coarser  particles 
are  separated  from  the  fine. 

Where  a  sufficient  head  of  water  can  be  obtained  and  the 
soil  to  be  washed  is  loose,  it  is  advantageous  to  convey  the 
water  directly  to  the  mass  by  means  of  hose  and  discharge 
it  through  a  1|  inch  nozzle  upon  the  earth  so  as  to  under- 
mine a  portion  of  it  and  cause  it  to  crumble  in.  This  is 
then  still  further  separated  and  dissolved  by  the  stream  and 
washed  into  and  through  ditches  200  or  300  feet  long,  having 
considerable  inclination  thereto ;  these  are  furnished  with 
grooves  in  which  the  metallic  particles  are  collected.  In- 
stead of  ditches,  troughs  made  of  boards  are  sometimes  used, 


300  MINERALS,   MINES,   AND   MINING. 

and  these  are  furnished  with  cross  pieces  on  the  bottom  in- 
stead of  grooves. 

ASSORTING  THE  ORE  IN  THE  MINE. 

The  useful  ore  must  be  separated  from  the  worthless  rock 
in  which  it  is  generally  contained.  The  'beginning  of  this 
work  is  made  in  the  mine  itself,  partly  to  obtain  rubbish 
with  which  to  fill  up  and  partly  to  save  transporting  useless 
material.  This  assorting  in  the  mine  cannot  be  very  close 
or  minute,  but  aims  only  to  separate  the  larger  pieces  which 
are  entirely  worthless  from  those  which  contain  ore. 

The  miner  looks  carefully  at  the  mass  obtained  by  a  blast, 
breaks  the  larger  pieces,  and  throws  the  worthless  to  one  side. 
The  rest  is  taken  away  and  more  narrowly  examined,  and 
assorted  first  as  to  the  size  of  the  pieces,  then  the  larger  pieces 
are  separated  into  richer  and  poorer. 

If  very  rich  ores  of  valuable  minerals  are  discovered  in  the 
mine,  they  are  carefully  separated  and  put  in  sacks  or  baskets 
and  carried  out  of  the  mine  immediately.  In  precious 
minerals  even  apparently  useless  ores  are  saved,  because 
even  a  very  low  per  cent,  of  gold,  or  silver,  will  pay  the  cost 
of  mining  and  smelting. 

TRANSPORTATION. 

This  whole  subject  may  be  conveniently  and  appropriately 
classified  under  one  head  : — 

1st.  Transportation  in  galleries  and  drifts  either  level  or 
with  an  inclination  not  exceeding  10°. 


TRANSPORTATION.  301 

2d.  Transportation  through  galleries  and  drifts  having  an 
inclination  of  more  than  10°  and  less  than  30°. 

3d.  Transportation  through  shafts  either  perpendicular  or 
inclined. 

General  Rules. — 1st.  Choose  the  shortest  way  and  sim- 
plest method. 

2d.  Avoid  as  much  as  possible  repeated  loading  and  un- 
loading, or  broken  transportation. 

3d.  Wherever  convenient  use  machinery. 

4th.  Be  not  afraid  of  expense  in  securing  the  best  means 
and  method  of  transportation. 

5th.  Do  not  hastily  or  frequently  change  the  transporta- 
tion from  one  drift  or  level  to  another  in  the  hope  of  saving 
distance. 

Transportation  through  galleries  and  drifts  having  an 
inclination  of  more  than  10°  and  less  than  30°. 

When  ore,  or  coal,  is  to  be  transported  from  a  higher  to 
a  lower  point  over  an  inclined  plane  one  method  usually 
adopted  is  that  represented  in  Fig.  60  (called  a  jigger 
break).  It  consists  of  a  winch  or  whim,  placed  at  the  point 
from  which  the  ore  is  to  be  transported  to  a  lower  gallery  or 
level  A.  Along  this  incline  double  wooden  rails  are  laid. 
R  is  an  axle-tree  around  which  a  rope  or  chain  is  wound 
several  times ;  at  the  upper  end  of  this  the  loaded  wagon  V 
is  fastened,  and  at  the  lower  the  empty  one  L.  When  the 
loaded  wagon  descends  it  draws  up  the  empty  one.  Now 
to  prevent  a  too  rapid  descent  a  wooden  wheel,  S,  is  attached 


302  MINERALS,   MINES,    AND   MINING. 

to  the  axle-tree,  and  this  again  is  provided  with  a  brake,  B, 
as  shown  in  Fig.  60. 

When  ore  is  to  be  transported  from  an  intermediate  drift, 
A,  Fig.  61,  the  wagon  may  be  attached  to  the  chain,  as 
there  shown,  provided  the  inclination  is  not  too  great.  On 
steeper  inclines  the  wagon  is  placed  on  a  platform,  (7,  as 
shown  in  Fig.  62.  The  object  is  to  prevent  the  ore  from 
falling  out  of  the  loaded  wagon  during  the  descent. 

Transportation  through  Shafts. 

The  method  of  shaft  transportation  depends  upon  the 
nature  of  the  shaft,  whether  it  be  perpendicular  or  inclined. 
The  machines  used  are  adapted  to  the  power  employed. 
The  windlass  is  worked  by  muscular  power,  the  water-wheel 
and  turbine  by  water-power,  the  steam-engine  by  steam- 
power. 

An  essential  requisite  for  shaft  transportation  is  found  in 
ropes.  Two  kinds  are  used,  hemp  and  wire.  The  former 
are  made  of  hemp  or  manilla  fibre,  the  latter  of  wire,  and 
both  either  round  or  flat.  Chains,  on  account  of  their  great 
weight,  are  not  much  used.  Round  ropes  are  wound  about 
cylindrical  or  conical  drums;  the  flat  ropes  or  bands  are 
wound  between  disks  (see  Fig.  63),  composed  of  two  flanges, 
-R72,  with  intermediate  space,  S  $,  for  the  band  or  flat  rope. 

The  shortest  and  most  natural  method  of  transporting 
minerals,  etc.,  from  a  higher  to  a  lower  plane  is  through 
shutes;.  these,  however,  must  have  such  an  inclination 
that.. .the  transportable  material  may  not  be  arrested  or 


PLATE  XII. 


FIG.  60. 


FIG.  61. 


FIG.  63. 


FIG.  62. 


To  face  page  302. 


TRANSPORTATION.  303 

"  hang"  in  its  course  ;  therefore,  they  should  not  be  curved, 
irregularly,  vertically,  or  laterally. 

If  the  shutes  are  lined  with  timber,  then  the  boards  should 
be  arranged  longitudinally,  that  is,  parallel  with  the  course 
and  securely  nailed. 

In  the  lower  plane  the  shute  terminates  with  or  without 
a  sliding  gate.  If  no  sliding  gate  be  provided,  a  recess  about 
six  feet  in  depth  should  be  made  (see  A,  Fig.  64),  which 
should  be  furnished  with  a  door  or  closed  by  strong  posts,  S, 
in  order  that  material  shall  not  fall  into  the  gangway  and 
interrupt  transportation.  If  the  shute  is  provided  with  a 
sliding  gate,  Fig.  65,  A  B,  the  surrounding  frame  should  be 
closed  up  with  strong  timbers,  and  only  the  opening  left  for 
the  sliding  gate  through  which  the  transportable  material 
falls  into  a  car  placed  below  or  is  raked  in.  In  order  that 
the  timbering  may  not  be  injured  by  the  material  rolling 
against  it,  the  shute  should  never  be  entirely  empty,  but  filled 
up  to  the  height  of  about  twelve  feet. 

The  windlass  is  efficient  in  transporting  material  from  a 
lower  to  a  higher  level  for  a  distance  of  twenty  fathoms 
(120  feet),  Fig.  66.  The  windlass  consists  of  a  framework 
and  drum  or  cylinder.  To  the  frame  belong  the  floor  frame 
B  B  G  G  and  the  posts  or  uprights  T  ^supported  by  the  braces 
S  S.  Into  the  uprights  the  cylinder  is  let  by  axles,  and 
around  the  cylinder  is  wound  a  rope  with  the  transported 
weight  or  bucket  at  the  end.  The  revolution  of  the  cylinder 
is  caused  by  the  cranks  which  form  the  continuation  of  the 
axles  which  turn  in  iron-lined  journals  let  or  "  scored"  into 
the  upright  (see  Fig.  67),  or  nailed  on  to  the  upright  (see 


304  MINERALS,   MINES,   AND   MINING. 

Fig.  68).  The  windlass  for  moderate  depths  is  generally 
worked  by  two  men,  and  for  greater  depths  three  and 
sometimes  four  men.  According  as  the  windlass  is  worked 
backward  or  forward,  one  or  the  other  vessel  descends. 

Where  a  windlass  is  to  be  erected,  a  wider  space  is  to 
be  excavated.  (Fig.  69.)  In  perpendicular  shafts  the  up- 
rights of  the  windlass  are  perpendicular  to  the  frame,  and  to 
make  them  more  secure  they  are  extended  and  let  into  the 
roof.  (Fig.  69.)  In  inclined  shafts  the  uprights  are  set  at 
right  angles  or  nearly  so  to  the  inclination  of  the  shaft,  mor- 
tising them  into  the  frame,  and  letting  them  into  the  roof. 
(Fig.  70.)  The  journals  are  fixed  at  two-thirds  of  a  man's 
height,  or  about  three  and  a  half  feet  above  the  floor,  taking 
care  that  they  be  upon  the  same  level.  The  cylinder  should 
be  at  least  nine  inches  in  diameter,  and  may  be  made  of  pine 
because  of  its  lightness  as  well  as  of  its  strength,  care  being 
taken  to  obtain  heart  timber  and  sound. 

If  a  greater  weight  is  to  be  raised,  and  from  a  greater 
depth  than  usual,  a  larger  and  stronger  cylinder  is  used, 
geared  in  with  cog-wheels,  the  larger  wheel  being  upon  the 
main  cylinder  and  the  small  cog-wheel  upon  a  separate  shaft, 
or  rod,  with  the  crank  attached.  The  cranks  should  not  be 
at  right  angles,  but  directly  opposite  each  other,  so  that  when 
one  is  down  the  other  shall  be  up ;  and  in  order  that  they 
shall  not  chafe  the  hands  of  the  workmen,  they  should  be 
furnished  with  cases,  or  shells  on  which  the  permanent 
handle  turns. 

The  hemp  ropes  are  generally  tarred  to  make  them  more 
durable.  In  mines  where  the  water  is  not  acid,  chains  with 


PLATE  XIII. 


FIG.  65. 


FIG.  68. 


FIG.  69. 


To  face  'page  304. 


PLATE  XIV. 


FIG.  70. 


FIG  72. 


FIG.  71. 


To  face  page  304. 


TRANSPORTATION.  305 

twisted  links,  may  be  used  to  greater  advantage  than  wire 
ropes.  The  ropes  must,  however,  be  three  or  four  fathoms 
longer  than  the  depth  of  the  shaft,  to  furnish  friction  enough 
by  sufficient  coiling  upon  the  cylinder. 

In  perpendicular  shafts  round  buckets  are  preferred,  in 
inclined  shafts  square  vessels  with  or  without  wheels.  In 
the  former  they  are  freely  suspended,  in  the  latter  they  slide 
or  roll  upon  rails  or  guides.  In  curved  shafts  the  rope,  or 
chain,  must  be  guided  by  rollers,  or  pulleys  placed  at  the 
parts  of  altered  direction. 

To  prevent  the  falling  of  material  into  the  shaft,  the  frame- 
work at  the  foundation  is  covered  with  flooring  into  which 
a  trap-door,  to  allow  transportation,  is  opened. 

When  the  depth  of  the  shaft  amounts  to  more  than  twenty 
fathoms  (one  hundred  and  twenty  feet),  the  windlass  must 
give  place  to  more  effective  machines.  The  more  common  are 
horse-whims,  water-wheels,  and  turbine  and  steam-engines. 
The  horse-whim,  Fig.  72,  consists  of  an  upright  cylinder 
post  TF,  with  drum  7T,  and  draft-beams  II.  The  cylinder 
is  made  of  hard  wood  and  revolves  upon  two  iron  axles, 
turning  on  cast-iron  centres  of  which  the  upper  one  is  fast- 
ened into  a  wooden  collar  beam  B  B,  and  the  lower  one 
turns  in  a  stone  block  G.  Around  the  drum  two  ropes  are 
wound  in  opposite  directions,  which,  during  the  revolution  of 
the  cylinders,  run  over  pulley-wheels,  Fig.  73,  into  the  shaft. 
The  manner  of  putting  together  a  drum  for  such  a  horse- 
whim  may  be  readily  understood  by  examining  the  follow- 
ing, Fig.  74,  the  spurs  being  preferable  to  a  smooth  periphery 
as  allowing  greater  hold  or  friction.  At  the  ends  of  the  ropes 

20 


306  MINERALS,    MINES,   AND   MINING. 

buckets  are  hung.  When  the  full  bucket  ascends  the  empty 
one  descends.  As  the  rope  of  the  descending  bucket  gradu- 
ally becomes  longer  and  heavier,  that  of  the  ascending  bucket 
becomes  shorter  and  lighter ;  in  this  manner  the  descending 
bucket  gradually  gains  in  weight  and  velocity.  To  equalize 
this  the  drum  receives,  instead  of  a  cylindrical,  a  double  conical 
form,  and  is  composed  of  two  frustums  of  cones  joined  at  either 
the  larger  or  smaller  ends — Figs.  75  and  76.  The  latter 
is  especially  used  in  the  horse-whims.  The  former  method 
finds  its  application  chiefly  in  the  water-whims,  and  both  are 
known  under  the  name  of  spiral  buckets,  and  they  are  gen- 
erally furnished  with  breaks.  When  such  a  whim  is  in  op- 
eration the  rope  of  the  ascending  full  bucket  winds  itself  in 
the  direction  of  the  greater  diameter  of  the  shaft,  that  is  the 
leverage  of  the  load  increases,  whilst  on  the  other  hand  the 
rope  of  the  descending  empty  bucket  winds  itself  about  the 
basket  in  the  direction  of  the  small  diameter,  and  thus  the 
leverage  decreases  so  that  the  power  and  weight  tend  to 
equalize  each  other. 

To  the  draft-beams  horses  or  other  animals  are  hitched, 
and  they  move  in  a  circle,  either  to  the  right  or  to  the  left, 
according  to  the  desired  movements  of  the  buckets. 

It  is  well  to  remember  that,  in  using  buckets,  it  sometimes 
is  a  great  convenience  to  have  properly  placed  in  the  bottom 
of  the  bucket  a  square  opening  fastened  by  a  strong  hinge 
on  the  one  side  and  by  a  small  movable  bar  of  metal  on  the 
other,  both  on  the  outside,  so  that  the  contents  of  the  bucket 
may  readily  be  discharged  upon  the  ground  without  turning 


FIG.  73. 


FIG.  75. 


FIG.  76. 


PLATE  XV. 

FIG.  74. 


To  face  page  306. 


TRANSPORTATION.  307 

or  tilting  the  bucket  over,  a  work  sometimes  attended  with 
great  effort. 

To  prevent  a  loaded  car  from  "  jumping  the  track,"  or 
parting  from  its  proper  course,  not  only  double  rails  may  be 
used,  but  one  single  elevation  in  the  midway  of  the  track 
may  be  found  both  cheaper  and  more  efficient,  as  represented 
in  Fig.  71,  wherein  the  car  is  supposed  to  be  lifted  up  at 
the  nearest  end  to  show  both  axles. 

The  principal  parts  of  a  water- whim  are  a  double  water- 
wheel  R,  Fig.  75,  constructed  with  a  brake  attachment,  and 
the  horizontal  rope  basket  K.  The  water-wheel  may  have 
a  diameter  of  from  three  to  thirty-six  feet,  and  differs  in  its 
construction  from  an  ordinary  overshot  water-wheel  only  in 
this  that  the  periphery  of  the  wheel  is  divided  into  two  sec- 
tions HH,  having  the  water-buckets  in  reversed  directions 
with  an  intervening  division  or  partition,  so  placed  that  a 
double  wheel  is  formed  which  may  be  turned  in  opposite  di- 
rections according  as  the  water  is  let  into  one  side  or  the 
other  of  the  wheel.  The  advantage  of  the  conical  basket 
is  the  same  as  in  the  horse-whims. 

The  brake  attachment  consists  either  of  a  separate  wheel 
B,  Fig.  75,  or  the  middle  of  the  water-wheel  is  raised  an 
inch  and  a  half  over  the  two  sides  and  the  brake  attached 
to  G.  A  very  simple  brake  consists  of  a  brake-frame,  T1, 
Fig.  77,  the  rods  SB,  the  draft-rods  Z Z,  and  the  brake- 
lever  H.  When  the  lever  is  depressed  the  rods  B  B  are 
pressed  against  the  wheel,  and  by  means  of  the  shoes  £  $ 
the  desired  friction  is  produced.  This  may  also  be  accom- 


308  MINERALS,   MINES,   AND  MINING. 

plished  by  turning  the  water  into  the  opposite  side  of  the 
water-wheel. 

Since  the  weight  decreases  as  the  bucket  ascends  the  head 
of  water  is  decreased,  and  when  the  bucket  has  nearly 
reached  the  surface  the  water  is  cut  off  altogether,  in  order 
to  stop  the  wheel.  This,  however,  can  only  be  fully  accom- 
plished by  means  of  the  brakes,  for  the  weight  of  the  water 
in  the  wheel-buckets  and  the  momentum  of  the  wheel  tend 
to  continue  the  motion. 

Another  method  is  as  follows :  The  descending  bucket  is 
filled  with  water  which  by  its  weight  draws  up  the  bucket 
filled  with  ore  and  other  material.  In  this  case  the  shaft  is 
furnished  with  either  a  horizontal  drum  for  round  ropes  or 
two  disks,  S  $',  Fig.  78,  for  band  or  flat  ropes  and  a  brake, 
B.  The  flat  ropes  run  over  pulleys  or  rollers,  R  R',  into 
the  shaft.  Where  conical  baskets  are  used  these  pulleys  or 
rollers  are  movable  along  their  axes,  in  order  to  follow  the 
lateral  movement  of  the  rope  from  side  to  side.  The  brake- 
wheel  is  situated  upon  the  same  cylinder  S  £',  and  has  on  its 
sides  pins,  Z  Z,  for  the  purpose  of  raising  or  lowering  the 
bucket  to  be  emptied. 

The  water  is  let  into  the  bucket  from  an  elevated  reservoir 
through  a  pipe  which  has  a  delivery  arm  and  hose  arid  stop- 
cock, T,  and  is  retained  in  the  bucket  bv  a  valve  in  the  bot- 

v 

torn. 

Since  the  mine  material  is  heavier  than  the  water  both 
buckets  must  not  be  equally  filled,  but  one  must  have  pro- 
portionably  less  weight.  For  this  purpose  the  buckets  have 
false  bottoms,  so  made  that  they  do  not  permit  the  water  to 


PLATE  XVI. 


FIG.  77. 


FIG.  78. 


To  face  page  308. 


TRANSPORTATION.  309 

come  in  contact  with  the  solid  contents,  but  to  enter  the 
space  below,  which,  when  it  is  desired,  may  be  filled  with 
water.  In  order  to  empty  the  bucket  when  it  reaches  the 
bottom  of  the  shaft,  a  valve  is  set  in  the  bucket  for  the  re- 
lease of  the  water.  This  method  of  lifting  is  of  value  only 
when  the  water  can  be  led  out  of  the  shaft  by  tunnel  or 
otherwise.  Instead  of  filling  the  descending  bucket  with 
water  it  may  also  be  filled  with  rocks,  provided  they  are 
called  for  filling  or  other  uses  in  the  mine,  as  suggested 
under  "Timbering  and  Masonry,"  p.  317. 

It  is  of  importance  to  put  the  whim  as  high  over  the  low- 
est adit  level  A  B,  Fig.  79,  as  the  distance  CD  is  below  the 
same,  so  that  both  buckets  may  be  at  the  place  of  loading 
and  unloading  at  the  same  time. 

Where  there  is  a  small  amount  of  water  with  sufficient 
head,  turbine  wheels  may  be  used.  They  present  the  appear- 
ance of  horizontal  wheels  (with  perpendicular  axes),  upon 
which  the  water  acts  by  thrust  and  weight  combined,  being 
caught  by  the  curvature  on  one  side  of  a  series  of  blades, 
which  are  concave  to  the  approaching  water,  but  convex  on 
the  opposite  side  to  the  same  body  of  water. 

The  general  form  and  curvature  of  the  blades  may  be 
seen  in  Fig.  80,  which  represents  a  horizontal  section.  The 
double  form  of  the  wheel  will  be  noticed,  the  outside  ring- 
wheel  being  made  stationary  and  the  inside  fastened  to  the 
shaft,  as  we  shall  further  explain,  in  Fig.  81. 

In  Fig.  81  may  be  seen  a  method  of  placing  the  wheel 
and  shaft.  Here  W  is  the  shaft,  the  wheel,  Fig.  80,  being 
at  the  lower  part  of  the  shaft  and  its  plane  at  right  angles 


310  MINERALS,    MINES,   AND   MINING. 

to  the  length  of  the  shaft  W.  At  the  top  of  the  shaft  is  the 
small  cog-wheel  X gearing  into  R,  which  runs  the  machinery. 
On  the  left  hand  is  the  main  delivery  pipe,  A,  the  box  receiving 
the  water,  which  turns  the  submerged  wheel  placed  between 
the  beams  S  S.  At  this  point  it  is  necessary  to  understand  that 
this  form  of  the  turbine  requires  that  firmly  placed  between 
S  S  is  the  outer  ring  of  the  wheel,  Fig.  80.  The  water 
descending  would  naturally  push  this  outer  ring  in  the  direc- 
tion of  the  arrow,  but  being  immovable  the  effect  is  to  move 
toward  the  opposite  direction,  the  inner  wheel  attached  to 
the  shaft  W.  Sufficient  room,  or  headway,  is  given  for  the 
water  to  escape  from  under  S  S.  It  is  plain  that  the  greater 
the  pressure  of  the  water  in  A  the  greater  will  be  the  force 
exerted  upon  the  curved  blades  of  the  turbine.  These 
principles  will  be  further  treated  of  in  the  examination  of 
special  cases. 

If  water  power  cannot  be  obtained  at  all,  or  only  at  too 
great  cost,  and  if  fuel  be  available  and  cheap,  it  is  better  to 
use  steam  power  for  transportation  and  other  work.  The 
effectiveness  depends  upon  the  expansiveness  of  steam,  and 
the  general  principles  upon  which  all  steam-engines  move 
may  be  learned  by  examination  of  Fig.  82,  with  the  expla- 
nations we  proceed  to  give. 

C  C  is  the  cylinder,  which  is  the  chief  and  head  place  of 
active  power  in  the  engine.  In  the  cylinder  is  the  piston 
head  7T  attached  to  the  piston  rod  L  L,  which  is  connected 
with  the  connecting  rod  MM  and  moving  with  the  motion 
of  the  crank  E  upon  a  joint  at  P  in  what  is  ordinarily  called 


PLATE  XVII. 


Fm.  79. 


FIG.  80. 


FIG.  81. 


FIG.  82. 


To  face  page  310. 


TRANSPORTATION-.  311 

the  cross  head  guided  on  either  end  by  the  guide,  or  guide 
rods.  A  is  the  fly-wheel,  whose  momentum  carries  the  con- 
necting rod  around  the  dead  centres ;  the  crank  E  is  now 
between  the  dead  centres  and  in  the  upper  semicircle.  // 
is  a  wheel  "  cogging  in"  to  the  larger  wheel  D  B,  which  thus 
carries  the  machinery.  Now  it  is  plain  that  steam  entering 
with  sufficient  pressure  behind  TTinto  C  G  will  press  K toward 
the  crank,  and,  contrariwise,  if  the  steam  was  let  in  on  the 
opposite  side  it  would  return  the  piston-head  K,  and  thus  the 
engine-shaft  would  turn.  This  oscillation,  however,  is  the 
result  of  a  constant  pressure  of  steam  entering  at  $,  and  at 
that  point  always  in  one  direction,  and  the  alternation  is 
brought  about  by  means  of  a  sliding  valve  JTin  the  steam- 
chest  Z  Z,  so  placed,  as  may  be  seen  in  Fig.  82,  that  only 
one  hole,  called  "port"  opens  the  steam  into  the  cylinder  at 
one  time.  In  the  figure  the  right  hand  hole  is  now  open 
and  the  steam  is  running  into  the  port  0,  at  the  same  time 
the  left  hand  lip  or  projection  of  the  slide-valve  has  covered 
the  left  hand  port,  and  no  steam  entering  there  the  pressure 
is  altogether  delivered  on  one  side  of  K.  But  there  must  be 
some  relief  from  the  resistance  of  the  steam  already  in  the 
front  part  of  the  cylinder  at  L  L.  This  is  obtained  through 
the  cavity  in  the  bottom  of  the  sliding  valve  X,  which  allows 
the  steam  now  useless,  and  called  the  " exhaust-steam"  to 
pass  out  of  the  same  port  through  which  the  "  live"  steam 
just  before  passed  in,  until  the  valve  slid  over  the  "port," 
so  far  as  to  allow  the  cavity  in  its  bottom  to  pass  the 
exhaust-steam  to  V,  when  it  escapes  into  the  open  air 
with  the  noise  which  all  non-condensing  engines  make. 


312  MINERALS,    MINES,   AND   MINING. 

After  this  front  movement,  it  is  plain  that  a  back  move- 
ment of  the  slide-valve  would  be  attended  by  an  uncover- 
ing of  the  front  (upper)  port,  the  passage  of  the  steam 
into  the  (lower)  front  port  O  and  the  consequent  reverse 
movement  of  the  piston-head  K,  the  steam  escaping  from 
behind  the  piston-head  as  before  it  escaped  from  before  the 
front.  It  now  remains  to  show  how  this  alternative  becomes 
automatic.  As  it  would  not  answer  to  make  the  movement 
of  the  slide-valve  greater  than  an  inch  or  two,  it  would  not 
do  to  connect  the  rod  G  G  with  the  crank  of  the  engine, 
hence  a  contrivance  called  the  "  eccentric"  or  eccentric  wheel 
F,  is  brought  into  use.  This  is  a  wheel,  or  circular  disk,  or 
plate,  placed  on  the  shaft,  but  not  so  that  the  two  centres  of 
the  shaft  and  eccentric  coincide,  but  the  latter  is  out  of 
centre  and  hence  the  name.  Around  the  periphery  of  this 
eccentric  is  a  groove  to  hold  the  circle  end  of  the  slide-valve 
rod.  It  is  plain  that  just  in  proportion  to  the  amount  of  dis- 
placement, or  eccentricity,  of  the  eccentric  will  be  the  amount 
of  draw  or  thrust  of  the  eccentric  rod,  and  if  the  centre  of  the 
shaft  and  the  centre  of  the  eccentric  wheel,  or  plate,  differ 
by  one  inch,  then  the  amount  of  movement  of  the  rod  will  be 
twice  the  amount  of  departure  of  centres  or  two  inches.  In 
this  way  the  eccentric  rod  may  be  made  to  move  from  the 
smallest  movement  to  as  great  as  the  size  of  the  eccentric  will 
permit,  remembering  that,  when  fitted  properly,  the  eccentric 
should  never  have  its  centre  cut  out  so  near  its  circumfer- 
ence as  too  much  to  weaken  the  edge  nearest  to  which  the 
hole  is  cut  out.  The  eccentric  can  move  around  the  shaft  and 
be  accommodated  to  any  desired  position  of  the  sliding  valve ; 


TRANSPORTATION.  313 

after  that  is  determined,  the  wheel  is  fixed  by  means  of  a 
"  key"  cut  half  way  in  the  shaft  and  half  in  the  eccentric 
wheel.  In  all  engines  much  efficiency  depends  upon  placing 
the  slide-valve  in  nice  adjustment,  that  is,  not  too  far  over 
one  port  and  too  little  over  the  other.  Eccentrics  should 
move  but  little,  hence  it  is  generally  preferable  to  cut  the 
ports  not  round,  nor  square,  but  in  rectangular  form,  so  that 
the  slide-valve  may  open  a  long  opening,  thus  letting  in  a 
larger  quantity  of  steam  by  the  same  draw  or  move  of  the 
eccentric  rod.  It  is  very  plain  that  an  eccentric  may  be  so 
large  as  seriously  to  detract  from  the  power  of  the  engine — 
hence  in  some  engines,  locomotives  especially,  the  ports  are 
very  narrow.  The  pressure  of  steam  upon  the  valve  of  an 
engine  is  in  some  cases  very  great,  and  although  the  power  lost 
or  expended  upon  mere  movement  of  the  valve  may  be  slight, 
the  difficulty  in  managing  the  starting-rod  or  lever,  in  some 
engines,  is  inconvenient  from  this  source  and  the  consequent 
wear  upon  the  valves  great.  Conical  valves  have  been  in- 
vented, as  in  the  Corliss  engine,  and  rollers  under  the  slide- 
valve  have  been  introduced  and  have  been  used  in  some 
locomotives,  but  not  generally  so. 

Nearly  all  engines,  in  large  operations,  whether  horizontal 
or  vertical  and  direct  in  acting,  or  with  "walking-beams"  (see 
Fig.  83,  A  A),  as  in  some  blowing  engines  on  the  Lehigh 
River,  at  Catasauqua  and  Hockendauqua,  Pa.,  and  Scran  ton, 
Pa.,  where  the  finest  and  largest  of  this  kind  are  to  be  found, 
owe  their  efficiency  to  the  mechanical  parts  just  described,  vari- 
ously modified  to  meet  a  variety  of  purposes.  Some  engines 
are  arranged  for  reversing  the  action  of  the  wheel,  a  con- 


314  MINERALS,   MINES,    AND   MINING. 

venience  which  becomes  in  some  mines  an  absolute  necessity. 
The  principle  is  easily  illustrated :  Thus,  suppose,  Fig.  82, 
that  the  part  of  the  eccentric  rod  G  G,  resting  on  the 
"  rocking  shaft,"  or  "  rock  bar"  Y  Yf,  itself  turning  or  "  rock- 
ing," that  is  oscillating,  at  H,  should  be  so  arranged  that 
the  end  at  Y  could  be  raised  to  Yf,  it  is  plain  that  a  draw  of 
the  eccentric  which  now  throws  Y  to  the  left  would  instantly 
throw  Y'  to  the  left  and  consequently  reverse  the  motion 
of  F,  and  this  would  reverse  the  movement  of  the  engine  and 
keep  it  running  on  this  reverse  till  the  end  ofGG  was  re- 
stored to  its  former  position  and  connection.  Various  inge- 
nious motions  have  been  invented,  especially  for  locomotives, 
and  adopted  in  various  engines  for  hoists  at  mines,  with  the 
object  of  quickly  reversing  the  engine. 

Thus  far  we  have  the  general  principles  of  the  steam- 
engine,  and  special  improvements  and  adaptations  will  be 
treated  of  in  another  place. 

TRANSPORTATION  ON  STEEP  INCLINES. 

In  cars  on  very  steep  inclines,  or  where  the  angle  of  in- 
clination changes,  the  wheels  are  in  some  cases  (Fig.  84)  run 
between  rails  S  /S,  and  the  boxes  or  cars  are  covered  so  that 
the  material  may  not  fall  out,  even  if  there  should  be  a  change 
of  slope  from  one  side  to  the  other  of  a  vertical  line.  One 
side  S,  is  partly  discontinued  in  the  drawing,  showing  the 
course  of  the  ore  from  the  car  T,  and  its  door. 

The  work  of  transportation  consists  of  the  running  of  the 
machinery,  filling  of  the  vessels,  displacing  and  replacing 


PLATE  XVIII. 


FIG.  83. 


FIG.  85. 


FKJ.  84. 


To  face  page  314. 


TRANSPORTATION   ON    STEEP   INCLINES.  315 

the  car  or  box  and  the  emptying.  Each  of  these  employ- 
ments demands  a  certain  expertness  and  care.  In  order  to 
give  expedition,  as  well  as  security  in  transportation,  various 
means  and  appliances  are  used  ;  for  example,  instead  of 
dumping  material  upon  the  ground  from  overhead  workings, 
it  is  always  advisable  to  dump  into  a  box,  barrel,  or  car,  and 
then  transport  the  car  to  the  place  of  delivery,  and  raise  the 
box,  barrel,  or  car  directly  up  to  the  surface.  (Fig.  85.)  A  still 
more  expeditious  method  is  to  use  cages,  generally  constructed 
with  iron  rods,  with  a  board  floor  and  iron  rails  for  the  box 
on  car-wheels.  These  cages  are  attached  to  the  rope  of  the 
shaft ;  the  full  car,  TF",  Fig.  86,  is  run  from  the  working  floor 
immediately  upon  the  cage  floor  and  securely  fastened  for 
hoisting  upwards,  whilst,  at  the  same  time,  another  cage 
with  an  empty  wagon,  or  car  descends.  To  prevent  lateral 
motion,  they  are  made  to  run  between  two  vertical  rails  by 
means  of  a  horse-shoe  clamp,  or  guide,  A  A,  and  in  order 
to  prevent  accident  from  falling  of  the  cage,  should  the  rope 
break,  safety  ratchets  fall  into  places  cut  to  receive  them 
when  the  rope  breaks. 

Another  kind  of  labor-saving  expedient  relates  to  the 
emptying  and  preservation  of  vessels.  These  arrangements 
consist  chiefly  in  movable  floor  or  sides  furnished  with  slide- 
bolts  or  springs  and  latches,  by  means  of  which  the  car  is 
opened  and  closed. 

Sometimes  the  emptying  is  effected  by  a  dump-cart  (see 
Fig.  84,  at  T).  In  some  cases  the  loaded  vessel  is  raised 
higher  than  the  mouth  of  the  shaft,  and  advantage  is  taken 
of  this  higher  grade  to  allow  the  loaded  vessel  or  car  to  pass, 


316  MINERALS,    MINES,   AND   MINING. 

by  gravity,  upon  a  tramway  to  a  distant  place  of  deposit  or 
delivery. 

Another  plan  is  to  raise  the  car,  then  rolling  it  off  aside  to 
an  inclined  shute,  attaching  a  hook  to  the  back  which  pre- 
vents the  car  from  passing  down  the  shute,  and  after  empty- 
ing returning  it  to  the  cage  or  platform  upon  which  it  was 
raised  from  below. 

FOR  INGRESS  OR  EGRESS  OF  WORKMEN  ladders  have  been 
used,  placed  at  an  angle  of  60°  to  70°  upon  landings,  or 
platforms,  twelve  feet  apart  (vertically) ;  the  openings  in 
the  landings  are  not  placed  immediately  under  each  other, 
but  alternately  on  one  side  of  one  landing,  and  on  the  other 
side  of  the  next.  Nothing  can  therefore  fall  directly  down. 
Fig.  87.  Where  the  depth  is  not  great,  climbing  trees  are 
used  (see  Fig.  88),  placed  at  a  considerable  angle,  not,  how- 
ever, too  horizontally,  and  the  cuts  deep  and  not  slanting, 
but  at  right  angles  to  the  treading  edge  and  side  of  the  tree. 

Another  plan,  suitable  for  narrow  ways,  is  by  a  series  of 
rounds  like  parallel  ladders,  down  which  the  workman 
passes,  placing  his  feet  alternately  upon  one  and  another 
round. 

All  these  consume  time  and  annoy  the  workmen  when  any 
depth  is  to  be  traversed ;  hence  other  and  more  effective 
methods  are  adopted. 

One  method  is  that  shown  in  Fig.  89,  wherein  are  repre- 
sented two  series  of  platforms  fastened  to  rods,  and  placed  at 
equal  distances,  and  so  worked  by  machinery  above  that 
they  move  alternately  upward  and  downward.  There  are 
hand-rails  represented  in  the  figure,  and  the  workmen  pass 


PLATE  XIX. 


FIG.  86. 


Fro.  87. 


FIG. 


FIG. 


FIG.  90. 


FIG.  91. 


Jo  face  page  316. 


TIMBERING   AND   MASONRY.  317 

alternately  from  one  to  another  platform  in  ascending  and 
descending. 

TIMBERING  AND  MASONRY. 

When  the  rock  of  a  mine  is  not  perfectly  firm,  it  has  to 
be  supported  and  pains  taken  to  guard  against  a  crush 
while  the  mine  is  made  accessible  in  all  its  parts.  This 
calls  for  the  work  of  mining-timbering  and  masonry. 

If  the  spaces  are  to  be  self-supporting,  this  rock  must  not 
only  be  firm,  but  whole,  and  the  form  of  the  spaces  must 
approach  the  circle  or  some  other  curve.  The  greater  or 
less  firmness  will  also  depend  upon  the  direction  in  which 
the  excavations  pierce  the  structure  of  the  rock.  A  tunnel, 
for  example,  which  runs  in  the  direction  of  the  strike  of  the 
rock,  or  a  shaft  whose  sides  are  parallel  with  the  same,  will 
not  be  so  secure  as  when  they  cross  that  direction. 

Well-known  means  of  supporting  open  spaces  in  mines 
are  by  pillars  of  native  rock,  or  that  left  standing  from 
original  rock,  and  supports  erected  from  waste  or  rejected 
material.  For  the  former  purpose,  that  rock  of  least  value 
is  used ;  if,  however,  valuable  ores  have  to  be  left  as  sup- 
ports, care  should  be  exercised  that,  at  some  later  period,  this 
material  may  be  recovered.  For  artificial  pillars,  the  rub- 
bish is  used,  or  if  the  ore  does  not  furnish  sufficient  rubbish, 
a  quarry  is  made  in  some  other  part  of  the  mine  or  rocks  are 
brought  from  the  surface.  An  underground  quarry  may  be 
made  by  digging  out  a  space,  supporting  it  for  a  time,  and 
then  permitting  it  to  crush  in,  thus  affording  material,  but 


318  MINERALS,   MINES,   AND   MINING. 

keeping  open  all  approaches  to  the  quarry.  The  bringing  of 
rock  from  the  surface  is  too  expensive  and  only  admissible 
in  extreme  cases,  and  then  such  rock  should  be  used  as 
counter-weight  in  drawing  up  useful  material  or  sent  down 
in  shutes,  if  possible. 

If  the  above-mentioned  simple  means  are  not  sufficient, 
timbering  or  masonry  has  to  be  resorted  to.  The  question 
is  which  of  the  two  may  be  most  suitable  and  advantageous. 
When  wood  is  scarce  and  not  always  attainable  and  expen- 
sive, and  when  because  of  the  great  frangibility  of  the  rock,  and 
the  great  pressure,  strong  and  heavy  timbering  is  necessary, 
or  when  on  account  of  imperfect  ventilation,  the  timbering 
must  be  frequently  changed,  and  further,  when  the  mine  is 
to  be  kept  open  a  long  time,  and,  finally,  when  in  or  near 
the  mine  good  and  cheap  stone  is  to  be  had,  there  and  then 
masonry  certainly  deserves  the  preference,  even  if  it  should 
cost  more  at  the  outset,  for  by  its  longer  duration  it  will 
abundantly  make  up  the  greater  first  cost.  Frequently, 
also,  a  dry  wall  may  be  constructed  with  great  advantage 
and  at  small  cost.  Before  either  method  of  timbering  or 
masonry  is  adopted  it  must  be  determined  from  which  side 
the  greater  pressure  comes,  arid  how  great  it  is. 

MINING  CARPENTRY. 

In  timbering,  much  depends  upon  the  nature  and  selec- 
tion as  well  as  the  preparation  and  placing  of  the  timbers. 
In  mining  timbers  as  a  general  fact  the  cone-bearing  trees — 
firs,  pines,  and  the  like — showing  acicular  leaves,  are  pre- 


MINING    CARPENTRY.  319 

ferred  to  the  broad  or  flat  leaf  bearing  trees.  However,  among 
the  latter,  the  oak  is  the  best.  Even  when  it  is  high  priced 
the  best  and  most  durable  wood  should  be  used,  because  the 
expense  of  frequent  renewal  is  avoided.  In  selecting  wood, 
choose  straight  pieces,  and  use  more  and  stronger  pieces 
according  to  the  pressure,  remembering  that  it  is  better  to  have 
too  much  than  too  little.  So  far  as  the  preparation  is  con- 
cerned, avoid  weakening  the  wood  by  too  much  cutting  away 
either  in  tenons,  or  in  dressing.  As  a  general  thing  timber 
is  used  unhewed,  in  order  that  none  of  its  strength  shall 

be  lost. 

In  regard  to  the  position  of  timber  it  is  a  well-known  fact 

that  every  piece  of  timber  can  support  a  greater  weight  lon- 
gitudinally than  laterally,  and  hence  vertically  than  horizon- 
tally, and  supports  the  greater  amount  of  pressure  at  right 
angles  to  the  grain.  So  also  in  pieces  of  the  same  thick- 
ness, a  short  piece  will  support  a  greater  weight  than  a  long 
piece. 

In  order  to  secure  greater  durability  in  timbering  the 
main  parts  of  it  are  let  into  the  rock.  Fig.  90  represents  a 
niche  cut  sloping  from  the  top  into  which  the  beam  falls  and 
is  held  permanently,  while,  at  the  opposite  side,  the  hole  is 
only  large  enough  to  receive  the  end  of  the  beam.  For 
measuring  accurately  two  rods  may  be  used,  which,  held  to- 
gether and  slid  outwardly,  may  be  marked  and  the  measure 
obtained  as  in  Fig.  91.  The  beam  is  then  cut  accurately,  so 
as  to  be  firmly  wedged  in  place.  Should  the  rock  on  either 
side  be  brittle  or  soft,  it  would  not  be  wise  to  put  the  ends 


320  MINERALS,    MINES,    AND    MINING. 

of  the  beams  immediately  against  it,  but  they  must  be  made 
to  rest  against  pieces  and  upon  plates  or  sills,  as  in  Fig.  92. 

The  timber  is  intended  to  be  either  permanent  or  tempo- 
rary. The  permanent  is  constructed  with  a  view  to  long 
duration,  the  temporary  for  only  a  short  time,  until  it  can  be 
replaced  by  more  permanent  timbering  or  masonry. 

If  in  a  gallery  or  drift  only  one  wall  overhanging  or  un- 
derlying is  to  be  supported,  it  is  done  by  putting  one  end  of 
a  cross-beam,  Fig.  93,  into  a  groove  of  solid  rock  and  wedg- 
ing the  other  end  firmly  or  tightly  against  the  wall  to  be 
supported.  Should  the  wall  itself  be  brittle,  a  wall-beam  R 
must  be  placed  against  the  wall  and  the  pillar  or  stay-beam 
be  securely  wedged  against  it,  Fig.  94.  Should  both  walls 
be  insecure,  two  such  beams  must  be  used,  Fig.  95.  In 
galleries  and  drifts  a  side  wall  is  secured  by  posts  let  into  a 
groove  at  the  bottom  and  wedged  against  the  weak  side, 
Fig.  96.  Should  the  side  be  firm,  but  the  roof  brittle,  the 
beams  are  put  into  the  grooves,  Fig.  97,  and  covered  with 
slabs.  Fig.  98  represents  the  method  of  timbering  in  ap- 
proaching movable  and  loose  masses  of  soil  or  rubbish,  also 
for  draining  and  ventilation,  being  the  strongest  timbering 
in  narrow  ways. 

When  the  side  and  the  roof  need  support  the  method  is 
as  represented  in  Fig.  99.  If  both  sides  and  the  roof  are  to 
be  secured,  three-quarter  frames  are  used,  as  shown  in  Fig. 
100,  or  whole  frames,  as  shown  in  Fig.  101.  The  frames 
consist  of  the  posts  S  8,  Fig.  102,  and  the  cross-piece  K. 
They  are  framed  into  each  other ;  the  projecting  parts  C,  I) 
are  called  the  foreheads  and  Eand  Ftiie  faces.  The  thickness 


FIG.  92. 


FIG.  94. 


To  face  page  320. 


PLATE  XXI. 


Fro.  96. 


FIG.  07. 


To  face  page  320. 


PLATE  XXII. 


FIG.  98. 


FIG.  99. 


FIG.  100. 


To  face  page  320. 


PLATE  XXITI. 


FIG.  101, 


FIG.  103. 


FIG.  104. 


FIG.  105. 


FIG.  106. 


,    To  face  page  320. 


MINING   CARPENTRY.  321 

of  the  posts  used  for  frames  is  generally  from  seven  to  nine 
inches.  Since  shorter  beams  can  sustain  (overhead)  a 
greater  pressure,  and  also  require  less  wood,  the  two  posts 
are  generally  made  to  incline  toward  each  other.  The  posts 
must  be  placed  at  right  angles  to  the  course  of  the  gallery 
or  of  direction  and  be  of  equal  height  or  length  in  order 
that  the  cross-beams  may  rest  upon  them  horizontally  and 
that  the  pressure  may  be  equally  distributed. 

The  method  of  framing  depends  upon  the  direction  from 
which  the  pressure  comes  and  upon  its  force  or  amount  of 
pressure.  Should  the  pressure  be  equal  upon  all  sides  and 
not  very  great,  then  the  cross-beam  is  placed  as  in  Fig.  103 ; 
but,  if  the  side  pressure  predominates,  then  as  in  Fig.  104; 
and  if  the  pressure  be  very  great,  then  as  in  Fig.  105.  Great 
pressure  from  above  is  met  with  frames  whose  posts  and  caps 
are  not  scored  in,  as  in  Fig.  106,  where  the  posts  at  the 
head  or  end  are  only  hollowed  out  to  receive  the  cap.  In 
order  that  the  posts  may  not  be  displaced,  projecting  spikes 
or  pins,  V  V,  are  driven  into  the  cap  pieces  close  to  the  posts. 
To  give  the  frame  a  still  greater  strength  additional  cross- 
wedges  or  braces  are  placed  between  the  posts  under  the 
caps,  as  in  Fig.  107,  and  kept  in  place  by  spikes. 

In  salt  mines,  posts  and  caps  are  formed  together  in  a  very 
simple  manner,  in  order  to  resist  a  very  great  and  uniform 
pressure.  The  posts  at  the  head  are  sawed  and  beveled  in 
such  a  manner  that  the  cap  lies  with  a  flat  face  upon  the 
head,  and  then  the  edge  of  the  inner  corner  of  the  post  is 
hewn  off,  as  in  Fig.  108,  B.  In  the  A  form  the  cap  log  is 

21 


322  MINERALS,   MINES,   AND   MINING. 

hewn  off  to  an  acute  angle,  that  the  lateral  pressure  may 
tend  to  a  more  nearly  vertical  direction. 

When  the  floor  is  loose  and  soft,  and  the  posts  are  liable 
to  sink,  ground  sills  have  to  be  placed  under  them,  as  in 
Fig.  109.  When  the  frames  are  near  to  each  other  long 
sills  are  preferred,  but  when  the  frames  are  some  distance 
apart  short  sills.  The  long  sills  6r,  Fig.  109,  are  unhewn 
logs  which  are  placed  in  the  corners  of  the  floor,  and  upon 
which  several  frames  are  erected.  When  the  pressure  upon 
the  sides  is  so  great  that  both  sills  and  posts  might  be 
crowded  into  the  gallery,  wedge  braces  have  to  be  placed 
•every  six  feet,  which  are  hollowed  out  at  the  ends,  as  on 
JS  S,  to  fit  the  long  sills  G.  The  short  ground  sills  G,  Fig. 
110,  are  placed  across  the  floor  of  the  gallery,  generally  let 
into  the  sides  of  the  gallery  rock-wall,  and  each  sill  carries 
it  own  frames. 

The  frames  are  placed  farther  apart,  or  nearer,  according 
to  the  greatness  of  the  pressure,  and  in  the  former  case,  if  the 
rock  be  liable  to  crumble,  the  lining  of  slabs,  or  split  logs,  or 
saplings,  Fig.  Ill,  are  used.  On  the  outside  of  the  frames, 
the  split  logs  are  placed  longitudinally  with  the  flat  sides 
towards  or  against  the  uprights,  and  the  empty  space  between 
them  and  the  walls  is  carefully  filled  in  with  rock. 

In  ground  altogether  crumbling,  or  where  old  works  are 
to  be  reopened  by  driving  piles  horizontally,  then  use  timber 
half  a  foot  wide,  and  made  of  split  or  sawn  timber  about  six 
feet  in  length.  When  a  loose  face,  or  breast,  of  a  gallery 
is  to  be  opened  and  timbered,  the  first  thing  is  to  set  an 
entire  frame  in  place  securely  and  then  drive  the  above- 


FIG.  107. 


FIG.  110. 


PLATE  XXIV. 

FIG.  108. 


FIG.  109. 


FIG.  111. 


To  face  page  322. 


PLATE  XXV. 


FIG. 112. 


FIG.  117. 


FIG.  113. 


FIG.  114. 


FIG.  115. 


FIG.  116. 


To  face  page  322. 


UNIVERSITY 


MINING   CARPENTRY.  323 

mentioned  wedges  or  piles  on  the  outside  of  the  frame  two 
or  three  feet  into  the  soil.  The  encompassed  mass  is  then 
removed  and  the  piles  are  driven  in  deeper.  Should  the 
ground  be  exceedingly  loose,  a  second  frame  has  to  be  erected 
before  the  piles  are  driven  a  second  time,  and  in  this  manner 
we  proceed  until  the  piles  are  driven  up  to  the  full  extent. 
(See  Figs.  112,  113.) 

In  the  case  when  the  sides  are  firm  and  only  the  roof  is 
brittle  or  soft,  a  cross-beam  A,  Fig.  113,  is  wedged  in  over 
head  ;  over  this  piles  are  driven  close  to  each  other  upon  a 
slight  rise  or  angle  of  ascent  until  they  have  penetrated  three 
or  four  feet.  When  the  dirt  is  taken  out,  a  second  beam  is 
placed,  and  then  a  third ;  then  a  new  beginning  is  made  at 
A,  and  then  proceeding  as  before. 

When  a  side,  or  drift  gallery,  is  to  be  opened  from  another 
and  timbered  gallery,  the  caps  of  the  old  gallery  are  sup- 
ported on  the  side  upon  which  the  new  drift  is  to  be  opened 
by  post  S,  Fig.  114,  and  a  cap  beam  or  collar  /;  then  the 
posts  of  the  old  frame  are  removed.  (Fig.  114.) 

If  the  floor  of  a  gallery  or  drift  is  to  be  prepared  for  trans- 
portation and  drainage,  a  timbered  floor  has  to  be  constructed, 
and  according  to  the  amount  of  water  to  be  drained  off,  this 
floor  is  raised  from  one  to  three  feet  above  the  ground.  (Fig. 
115.)  In  galleries  untimbered,  this  is  accomplished  by  plac- 
ing in  distances  of  six  to  twelve  feet  cross-beams  from  four 
to  eight  inches  square  let  into  the  wall-sides  upon  which  the 
flooring  is  placed.  In  timbered  galleries  the  cross-beams 
are  placed  between  the  posts  of  the  frames,  as  in  Fig.  116. 
In  placing  the  boards  they  should  be  closely  joined  and 


324  MINERALS,   MINES,    AND    MINING. 

fastened  down  with  wooden  pins.  When  the  vein  pitches 
considerably,  so  that  the  floor-beam  cannot  be  let  into  both 
sides,  as  in  Fig.  117,  the  post  or  sill-beam  Tis  first  let  into 
the  rock,  and  the  floor-beam  S  is  secured  upon  this. 

The  floor  must  have  not  only  a  direction  parallel  with  the 
course  of  the  gallery,  but  also  be  horizontal  from  side  to 
side ;  therefore  the  boards  before  they  are  nailed  are  tried 
with  the  level,  or  by  pouring  a  little  water  in  a  trough  placed 
upon  them. 

When  the  water  is  drained  off  upon  one  of  the  sides  in  a 
ditch  or  gutter  (Figs.  17,  18)  then  the  board  floor  rests  im- 
mediately upon  the  rock  floor  of  the  gallery  on  proper  joists 
or  scantling. 

Floor  for  transportation  is  either  a  common  open  floor  or 
tight  floor;  an  open  floor  has  only  a  single  board  B,  Fig.  116. 
A  tight  floor  is  an  entire  covering,  used,  not  only  for  trans- 
portation, but  for  ventilation.  (Fig.  115.) 

TIMBERING  OF  SHAFTS. 

It  is  seldom  the  case  that  shafts  are  sunk  for  their  entire 
distance  in  solid  rock  which  requires  no  support.  As  a 
general  thing  all  shafts  require  more  or  less  timbering. 
This  cannot  be  made  permanent  at  once,  but  a  preparatory, 
or  temporary,  timbering  has  to  be  used  at  first. 

Timbering  of  shafts  is  thus  commenced  :  upon  the  leveled 
ground  the  frame  is  laid ;  this  frame  consists  of  oak  beams, 
ten  by  twelve  inches,  and  the  length  according  to  the  size  of 
the  shaft,  allowing  from  two  to  three  feet  for  the  projections 


PLATE  XXVI. 


FIG.  118. 


FIG,  120. 


FIG.  119. 


FIG.  121. 


To  face  page  324. 


TIMBERING    OF    SHAFTS.  325 

over  the  frame  which  are  intended  to  be  let  into  the  sides  of 
the  shafts.  (Fig.  118.)  When  the  shaft  is  sunk  from  the  sur- 
face, the  first,  or  "day  frame,"  has  to  be  raised  and  set  higher 
than  the  shaft  mouth  to  obtain  height  of  level  for  discharging 
material.  This  frame  should  be  set  to  the  exact  position 
intended  for  the  shaft,  and  the  subsequent  excavation  is 
measured  by  a  plumb  line  from  its  corner.  To  extract  mate- 
rial a  windlass  is  erected  and  also  a  pump,  if  necessary  to 
remove  the  water. 

As  long  as  the  excavation  proceeds  through  insecure  rock, 
temporary  timbering  of  unhewn,  but  of  barked  wood  is  used. 
For  this  purpose  holes  are  made  into  the  corners  of  the 
shorter  sides  into  which  the  beams  /,  /,  Fig.  119,  are  placed; 
these  are  kept  apart  by  cross-beams,  E  E  E,  according  to 
the  number  of  divisions  the  shaft  shall  contain.  These  parts 
are  concave  at  the  ends  to  fit  the  other  timber,  and  all  these 
timbers  when  placed,  as  in  Fig.  119,  constitute  a  lock  frame. 
When  the  rock  is  very  friable,  the  locks  are  placed  two  and 
three  feet  apart;  when  the  rock  is  firmer,  they  may  be  farther 
apart.  On  the  outside  of  these  frames  casings  or  linings  are 
placed,  as  in  Fig.  120. 

When  the  shaft  has  proceeded  with  temporary  timbering  for 
some  distance,  and  this  is  no  longer  sufficient  for  the  pressure, 
steps  must  be  taken  for  the  erection  of  permanent  timber. 
This  must  be  begun  by  preparing  a  firm  foundation.  For 
this  purpose  holes  are  made  into  the  long  sides  of  the  shaft 
corresponding  with  the  partitions  of  the  shafts,  and  into 
these  cross-beams  TTT(F'ig.  121)  are  placed;  these  beams 
are  square,  and  intended  to  carry  the  rest  of  the  timbering. 


326  MINERALS,   MINES,    AND    MINING. 

Should  the  rock  be  insecure,  long  beams,  Z,  are  let  into  very 
deep  holes  in  the  shorter  shaft  sides,  and  upon  these  cross- 
beams, T7,  are  placed,  and  to  obtain  still  greater  security 
braces,  /S,  are  placed  between  the  long  beams  under  the  cross- 
beams or  ties.  Such  foundation  frames  are  placed  at  distances 
of  from  one  to  four  fathoms,  according  to  the  firmness  of  the 
soil.  If  the  ground  is  not  sufficiently  firm  for  the  holes  of 
the  beams,  they  have  to  be  furnished  with  ground  plates  and 
sills,  as  shown  in  Fig.  95. 

The  lining  of  shaft  timbering  may  be  constructed  in  three 
ways,  as  in  Fig.  122,  which  is  a  vertical  cross  section,  wherein 
the  uprights  R  R  are  placed  vertically  between  the  two  cross- 
beams T  T7,  and  to  secure  them  still  further  the  diagonal  braces 
G  G  G  serve  to  hold  the  lining  logs,  or  slabs,  against  the  sides 
of  the  shaft.  This  is  especially  suitable  for  the  shafts  wherein 
the  only  long  sides  A  B,  A  B  are  insecure.  In  the  second 
method  the  lining  boards  are  vertically  placed  (Fig.  123), 
and  the  frames  are  placed  upon  stub-pillars  at  the  corners, 
the  partition  cross-pieces  are  let  into  the  longer  beams,  and 
to  prevent  the  striking  of  the  buckets,  may  be  lined  inside 
with  timbers  vertically  placed.  The  frames  are  distant  apart 
not  more  than  three  feet,  the  sub  pillars  being  proportionate. 
This  method  is  adapted  to  a  firmer  rock  where  the  pressure 
is  uniform  upon  all  four  sides.  The  space  behind  the  lining 
must  be  filled  up.  This  method  of  lining  does  not  require 
hewn  timbers,  but  it  is  sufficient  if  the  frame  which  rests 
immediately  upon  the  foundation  frame,  and  every  alternate 
one,  be  of  hewn  timber. 

The  third  method,  shown  in  Fig.  124,  which  consists  of 


FIG.  122. 


FIG.  123. 


FIG. 126. 


PLATE  XXVII. 

FIG.  125. 


FIG.  124. 


FIG.  127. 


To  face  page  326. 


TIMBERING    OF    SHAFTS.  327 

frames  placed  one  on  top  of  the  other,  is  used  when  very 
great  pressure  has  to  be  resisted  and  the  ground  is  very  loose. 
In  order  that  no  linings  may  be  required,  hewn  timbers  are 
used  for  the  frames.  Instead  of  joining  them  together  by 
half  tenoning,  as  in  Fig.  124,  they  may  also  be  joined  by  a 
mitre  cut,  as  in  Fig.  125. 

When  all  the  sides  of  a  shaft  do  not  need  timbering,  the 
firm  side  is  left  open.  Supposing  one  of  the  long  sides  needs 
timbering,  then  the  beam  is  let  into  the  side,  as  in  Fig.  126, 
and  held  against  that  side  by  the  cross  beams  R  R,  which 
are  concave  against  the  sustaining  beam,  and  let  into  the 
wall  at  the  other  ends.  (Figs.  126,  127.) 

In  Fig.  127,  we  have  the  method  of  timbering  when  the 
short  sides  need  timbering,  and  the  long  are  firm. 

When  only  portions  of  the  shaft  need  timbering,  either 
one  or  other  of  the  already  described  methods  may  be  used 
as  needed. 

As  in  the  case  of  galleries,  so  in  shafts,  it  may  be  neces- 
sary to  proceed  to  pile-driving,  as  in  Fig.  128.  When  the 
piles  have  been  driven  down  from  three  to  four  feet  below 
the  upper  frame  $,  and  the  loose  material  has  been  taken 
out,  then  follows  a  second  local  frame  $',  and  between  the 
two,  posts  may  be  put  at  the  corners,  should  it  be  necessary. 
Therefore  the  piles  are  driven  deeper  into  the  ground,  and 
the  method  of  procedure  is  as  before. 

When  perpendicular  shafts  have  several  divisions,  these 
must  be  timbered  to  answer  the  purpose  for  which  they  are 
to  be  used.  When  one  is  to  be  used  by  the  miners  alone, 
it  is  separated  from  the  transporting  shaft  by  a  partition, 


328  MINERALS,   MINES,    AND    MINING. 

Fig.  87,  V,  which  is  nailed  to  the  partition  beams.  Within 
the  partition,  platforms  are  made  twelve  feet  apart  upon 
which  the  ladders  are  placed,  as  in  Fig.  87. 

In  the  transporting  division,  care  has  to  be  taken  that  the 
buckets,  or  other  vessels,  do  not  strike  or  catch  on  the  sides. 
In  the  other  division  (pumping  or  ventilating)  platforms, 
similar  to  those  in  Fig.  87,  are  erected  for  the  purpose  of 
examining  the  machinery,  and  keeping  it  in  order.  The 
mouth  of  a  gallery  opening  into  a  shaft  ought  to  be  provided 
with  doors  or  way-boards  to  prevent  accident.  When  a 
transporting  gallery  opens  into  a  shaft,  a  place  for  filling  the 
vessels  has  to  be  prepared.  In  order  to  its  complete  timber- 
ing, long  ground  sills  are  placed  along  its  two  sides,  G  G  G, 
Fig.  129.  Upon  these  posts,  S  S,  are  placed  nicely  fitted, 
and  therefore,  perhaps,  concave  at  the  lower  ends;  and  upon 
the  latter,  long  joists  //,  driven  firmly  against  the  ceiling, 
or  upper  wall,  and  when  from  friability  of  this  wall,  or  great 
pressure,  additional  lining  is  needed,  then  an  additional 
joist  M is  used  with  its  corresponding  support.  This  arrange- 
ment is  adopted  when  a  larger  chamber  is  demanded  whose 
width  is  greater  than  that  of  the  gallery.  Where  such  a 
chamber  is  situated  in  solid  rock,  all  that  is  required  is  to 
provide  timbering  for  it  where  it  opens  into  the  shaft.  Here 
a  sort  of  door-frame  is  erected.  For  this  purpose  holes  are 
cut  in  the  short  sides,  and  a  heavy  sill  is  placed  along  the 
edge  of  the  long  sides  G,  Fig.  130  ;  a  joist  /  corresponding 
with  the  ceiling  of  the  chamber  furnished  with  tenon  holes 
into  which  the  posts  S  S  are  fitted.  These  spaces  thus 
formed  are  either  closed  permanently  as  at  A,  or  doors,  T  T, 


FIG.  128. 


FIG.  129. 


FIG.  130. 


PLATE  XXVIII. 

FIG.  131. 


FIG.  132. 


To  face  page  328. 


TIMBERING    OF    INCLINED    SHAFTS.  329 

are  provided  which  open  into  the  chamber,  and  during  the 
working  hours  are  closed,  and  may  be  during  other  hours. 
Above,  just  below  the  joists,  are  placed  two  rollers  W  TF", 
projecting  slightly  into  the  shaft  to  prevent  friction  on  the 
joists  when  the  vessel  is  drawn  up.  As  a  safety  for  the 
miners,  supports  K K  are  firmly  fastened  upon  the  two  up- 
rights S  S.  The  space  of  the  chamber  is  generally  divided 
off  by  posts  into  several  partitions  for  the  reception  of  dif- 
ferent kinds  of  material,  and  platforms  are  erected  inclining 
toward  the  gallery  away  from  the  shaft. 

TIMBERING  OF  INCLINED  SHAFTS  (SLOPES). 

In  slopes,  the  roof  generally  needs  the  most  support. 
When,  therefore,  it  is  not  perfectly  safe,  joists  /,  Fig.  131, 
are  laid  across  the  shaft,  and  propped  up  by  posts  S,  truly 
fitted.  These  are  perpendicular  to  the  direction,  and  placed 
in  holes,  or,  when  necessary,  upon  floor  joists,  as  seen  in 
Fig.  131  at  G  G.  These  are  placed  nearer  or  farther  apart, 
as  determined  by  the  nature  of  the  rock  or  ground.  When 
the  overhanging  rock  is  very  brittle  and  unsafe,  the  joists 
are  placed  very  near  together.  (See  Fig.  132.)  Under  them 
are  placed  long  plate  beams  supported  on  posts  S  S  S,  and 
with  diagonal  braces  Z  Z,  if  necessary,  as  seen  in  the  figure  ; 
and  also  when  necessary  a  ground  sill  is  used.  When  the 
roof  is  firm,  separate  posts,  S,  are  needed  only  for  partitions 
of  the  inclined  shaft,  which  are  let  into  holes,  or  placed  upon 
sills  and  to  which  slabs  or  boards  are  nailed.  The  partition 
through  which  the  miners  pass  is  furnished  with  platforms 
B,  or  steps  T,  Fig.  133.  The  former  are  placed  upon  the 


330  MINERALS,   MINES,    AND   MINING. 

ground  floor  from  the  overhanging  to  the  underlying  wall 
and  the  cleets  or  steps  on  the  underlying  wall.  These  cleets 
must  have  sufficient  depth  so  as  to  hold  the  post.  There  is 
also  a  hand-rail,  as  seen  in  Fig.  133.  For  transporting  ves- 
sels having  wheels  the  floor  of  the  inclined  shaft  is  fitted 
with  a  tramway,  or  rail-track  of  ordinary  iron  or  wooden 
rails,  or  such  as  represented  in  Fig.  70,  or  as  in  Fig.  84. 

Shutes  or  transporting  shafts,  used  also  for  miners'  way, 
must  be  provided  with  a  strong  partition  (see  Fig.  134),  and 
the  shute  itself,  if  it  be  irregular  in  inclination,  should  be 
furnished  with  a  board  floor  in  order  that  the  material  may 
the  more  readily  slide  down. 

On  the  mouth  of  any  shaft  a  shed  should  be  built  at 
first  for  the  windlass  and  pump,  and  at  a  later  period,  when 
the  shaft  has  been  driven  deeper,  and  machinery  is  necessary, 
a  larger  head-house  should  be  built. 

TIMBERING  NECESSARY  FOR  WORKING  IN  MINES. 

The  open  spaces  arising  from  abstraction  or  withdrawal 
of  mineral  deposit  demand  special  timbering.  In  working 
overhead  when  the  roof  has  been  hewn  away  to  a  certain 
extent,  and  the  gallery  beneath  is  to  remain  open,  a  timber 
ceiling  is  prepared  by  placing  joists  E,  Fig.  135,  across  the 
gallery  at  the  usual  height,  which  joists  are  let  into  the 
walls  and  covered  with  suitable  lining  or  flooring,  and  upon 
this  rubbish  is  cast.  In  very  steep  veins  the  joist  is  placed 
as  shown  in  Fig.  135  by  dotted  lines  E',  in  order  that  the 
underlying  rock  may  bear  more  of  the  weight.  When  the 
overhead  working  has  proceeded  for  some  distance,  and  the 


PLATE  XXIX. 


FIG. 133. 


FIG.  134. 


FIG.  135. 


FIG.  136. 


To  face  page  330. 


FIG.  137. 


PLATE  XXX. 


FIG.  138. 


FIG.  139. 


FIG.  140. 


Fig.  141. 


FIG.  142. 


FIG.  143. 


To  face  page  330. 


RENEWING   TIMBERING.  331 

mass  of  rubbish  becomes  too  heavy  for  the  first  set  of  timbers, 
as  in  Fig.  136,  K,  then  at  suitable  distances  other  timber 
has  to  be  provided,  as  K ',  in  order  to  distribute  the  weight 
of  the  rubbish.  When  a  vein,  or  lode,  has  considerable 
thickness,  and  the  joist  E,  Fig.  137,  as  a  consequence,  has 
to-be  long,  it  is  supported  by  posts  &  8.  In  working  down- 
ward on  benches,  as  in  Fig.  138,  where  A  B  represents  the 
floor  of  the  gallery  which  has  been  cut  away  and  replaced 
by  timbers,  the  method  of  procedure  is  as  follows :  Joists,  as 
under  A  B,  are  placed  in  holes  in  the  sides  of  the  wall  and 
a  suitable  floor  upon  them.  Now,  as  the  steps  descend,  still 
lower  additional  floors,  KK\  are  constructed  to  receive  the 
rubbish. 

In  taking  out  the  ore  from  large  deposits,  the  method  of 
timbering  is  essentially  the  same  as  that  already  described, 
only  on  a  greater  scale.  Sometimes  it  is  sufficient  to  use 
simply  posts  or  props  (see  Fig.  139),  or  box  pillars  may  be 
used,  or  door-frames  with  several  posts,  as  in  Fig.  140,  or 
the  method  is  adopted  as  suggested  in  Fig.  129.  It  must 
be  borne  in  mind  that  in  timbering  larger  spaces  stronger 
timbers  are  needed,  and  a  method  of  joining,  or  combining 
them,  which  will  give  the  greatest  resistance  or  durability. 

RENEWING  TIMBERING. 

When  a  timber  decays,  or  when  a  break  occurs  in  the 
same,  the  insecure  has  to  be  replaced  by  that  which  is  new 
and  strong.  For  this  purpose  the  timbering  should  be  con- 
structed in  the  beginning  so  as  to  facilitate  these  repairs, 
that  is,  in  such  a  manner  that  any  piece  may  be  taken  out 


332  MINERALS,   MINES,   AND    MINING. 

and  replaced  by  another  without  tearing  to  pieces  the  whole 
frame.  These  repairs  should  be  made  in  good  time,  so  that 
danger  or  loss  may  be  avoided. 

When  single  frames  are  to  be  replaced,  the  new  cap  is 
put  against  the  ceiling,  the  posts  are  put  into  the  holes,  and 
driven  or  wedged  against  the  cap  in  order  that  the  posts 
may  not  yield.  Pegs,  as  in  Fig.  106,  are  driven  in,  or  cross- 
braces  are  used,  as  in  Fig.  107.  In  replacing  shaft  timbers, 
the  work  proceeds  from  below  upwards.  The  support  of 
the  upper  portion  must  precede  the  work.  The  first  thing 
is  to  erect  a  firm  platform  at  the  place  where  the  repairs  are 
to  be  made.  The  beams  upon  which  the  platform  rests 
may  be  placed  upon  the  lock-frames  represented  in  Fig.  122, 
T  T,  or  upon  any  of  the  frames,  Fig.  1 23 ;  but  where  the  shaft 
is  timbered  according  to  the  method  in  Fig.  124,  holes  for  the 
reception  of  beams  six  feet  apart  vertically  ought  to  be  left. 
(See  Z,  Fig.  124.)  Before  a  frame  is  removed,  the  one  im- 
mediately over  it  is  propped  up  securely  by  braces  until  the 
defective  frame  is  removed  and  the  new  put  in  its  place. 
Where  single  frames  are  to  be  removed  from  shafts,  as 
shown  in  Fig.  124,  posts  or  timbers  which  have  the  ends 
fitted  to  the  proper  curvature  are  wedged  in  upon  the  sides 
separately,  that  is,  one  by  one. 

MASONRY. 

Walls  of  the  gallery  are  either  wet-laid,  or  are  dry  walls, 
that  is,  laid  in  mortar,  or  without  mortar ;  straight  or  curved, 
level  or  arched.  In  ordinary  walls  the  stones  are  laid  flat 
and  the  wall  rises  perpendicularly.  In  arched  masonry,  the 


MASONRY.  333 

stones  receive  a  wedge-shape  form  and  the  walls  ascend  in 
a  curve. 

A  durable  masonry  requires  good  and  suitable  materials,  a 
firm  foundation  and  exact  joining  of  the  stones.  The  most 
suitable  building  stones  are  thick  table  pieces  with  broad, 
long,  flat  faces.  In  arched  masonry  the  stones  are  gene- 
rally specially  prepared. 

In  order  to  prepare  good  common  mortar,  from  six  to  ten 
parts  of  sand  are  taken  to  one  of  lime  slaked ;  the  mass  is 
stirred  while  the  water  is  being  added,  and  it  is  best  to  make 
only  as  much  as  can  be  used  up  in  one  day.  When  walls 
are  to  be  built  in  a  damp  place,  or  where  there  is  a  great 
deal  of  water,  it  is  better  to  use  hydraulic  mortar  which 
hardens  in  the  water.  This  is  prepared  by  adding  hydraulic 
cement  or  plaster  of  Paris.  Such  an  addition  is  of  advantage 
to  common  mortar  because  mines  always  are  more  or  less 
damp.  The  foundation  of  the  walls  should,  if  possible,  be 
made  in  the  solid  rock,  but  when  this  canno^be  done,  large 
stones  should  be  used  or  arches  constructed. 

For  a  proper  joining  of  stones  it  is  necessary  that  they 
should  lie  flat  upon  each  other,  and  that  some  should  be 
used  as  runners,  that  is,  presenting  a  long  face  on  the  wall 
front,  and  others  as  binders,  that  is,  running  inwards  and 
across  the  wall  from  front  backward. 

It  is  of  course  understood  that  each  stone  shall  cross  the 
joints  of  two  others  underlying  (see  Fig.  141),  or,  as  it  is 
called, "  break  joint ;"  the  outward  faces  ought  not  to  project, 
but  must  fall  in  line  in  one  plane,  and  the  interstices  should 
be  filled  with  spalls  and  mortar,  and,  in  dry  walls,  with  moss 


334  MINERALS,    MINES,   AND   MINING. 

and  spalls.  Behind  the  wall  this  space  should  be  completely 
filled  up  either  by  rubbish  or  dry  wall. 

Before  beginning  a  wall  a  sufficient  space  has  to  be  cleared  ; 
in  order  to  do  this  the  gallery  is  made  larger,  when  first  driven, 
by  the  thickness  of  the  walk  to  be  put  up,  or  enlarged  after- 
wards ;  then  the  direction  and  the  amount  of  pressure  have  to 
be  determined ;  the  greater  the  pressure  the  thicker  the  wall, 
and  its  main  strength  is  applied  toward  the  main  pressure. 
The  strength  of  a  wall  depends  upon  its  thickness,  the  proper 
joining  of  the  stones,  and  upon  the  size  of  the  stones.  Small 
stones  are  more  difficult  to  be  united,  and  require  more 
mortar,  and  afford  on  that  very  account  less  strength. 

To  oppose  or  resist  a  slight  pressure  upon  the  sides  it  is 
frequently  sufficient  to  erect  a  dry  wall,  and  a  mortar  wall 
is  certainly  strong  enough.  To  give  to  such  a  wall  a  firmer 
position,  the  ground  is  excavated  to  some  depth,  and,  on  the 
side  of  the  pressure,  the  foot  of  the  wall  is  made  to  slope  or 
slant  downwai^  toward  the  pressure,  as  A  in  Fig.  142.  A 
level  wall  is  used  also  when  galleries  are  to  be  constructed 
in  large  excavated  spaces.  The  wall  is  built  up  of  large 
pieces  of  rock  and  filled  up  behind  to  the  overhanging  and 
underlying  wall  to  the  limits  of  the  chamber.  On  top  of 
the  wall  caps  or  joists  are  placed  which  are  covered  with 
suitable  covering  and  walled  over  or  covered  with  rock. 
(Fig-  143.) 

Where  great  strength  and  durability  are  required  arched 
masonry  is  used.  The  arch  and  the  semicircle  are  the  curves 
generally  employed,  also  small  segments  of  a  circle,  and  the 
ellipse,  which  has  either  an  egg  shape,  an  oval,  or  elliptical, 


MASONRY.  335 

as  the  pressure,  the  height  and  width,  etc.,  may  demand.  In 
arched  masonry  or  in  vaults  we  distinguish  the  span,  the 
height,  and  the  strength.  By  the  span  is  meant  the  length 
of  the  arch,  or  the  distance  A  B,  Fig.  144,  measured  between 
the  two  feet  of  the  arch  inside.  By  the  height  is  understood 
the  perpendicular  distance  from  A  B  to  the  highest  point 
of  the  arch  D.  The  thickness  or  strength  of  an  arch  is  rep- 
resented in  the  figure  by  the  thickness  of  the  wall.  The 
supports  for  the  feet  of  the  arch  are  called  the  holding. 

The  arches  themselves  are  either  whole,  that  is,  closed  on 
all  sides,  or  half,  that  is,  such  as  have  only  a  half  of  the 
curved  line ;  or  partial,  that  is  when  the  curve  is  smaller 
than  a  semicircle. 

The  length,  or  span,  and  the  height  of  the  arch  stand  in 
a  certain  relation  to  each  other,  that  is,  for  any  six  feet  of 
length  two  feet  of  height  are  usually  reckoned.  When  the 
span  is  greater,  the  height  is  usually  shorter  than  the  above 
ratio  in  proportion,  in  order  that  the  vault  may  not  occupy 
too  much  room  and  require  too  much  labor  in  its  erection. 
But  since  its  supporting  power  is  thereby  weakened,  it  re- 
ceives greater  thickness.  The  height  of  the  arch  must  be 
proportioned  to  the  pressure,  and  in  such  a  way  that  all  the 
vaulting  may  have  a  uniform  direction  to  the  centre.  The 
beds  are  hewn  into  the  solid  rock  or  prepared  by  masonry. 
The  surfaces  must  lie  in  the  same  line  with  the  radii  C  A, 
C  B,  which  determine  the  arch.  Fig.  145. 

In  order  to  give  to  an  arch  the  proper  curve,  forms  or 
patterns  are  made  of  boards.  These  are  joined  together  and 
cut  according  to  the  curve  desired,  and  then  so  placed  that 


336  MINERALS,   MINES,    AND   MINING. 

the  arch  may  be  built  upon  it.  The  radius  of  the  form,  or 
curve,  must,  however,  be  from  one  to  one  and  a  half  inch 
shorter  than  that  of  the  desired  curve,  because  upon  these 
forms  a  shield  is  nailed  upon  which  the  arch  is  built. 
Moreover,  these  patterns  must  be  so  placed  as  not  to  obstruct 
the  free  passage. 

Fig.  146  represents  the  form  for  a  semicircular  arch.  At 
N  Q.  nail  is  driven  to  which  the  string  is  tied  for  describing 
the  curve.  Instead  of  disposing  the  boards  as  in  Fig.  146, 
they  may  be  placed  as  in  Fig.  147,  where  the  nail  is  driven 
into  a  stake  at  P,  and  the  boards  so  placed  as  to  receive  the 
curve  symmetrically.  Only  when  the  curve  has  been  de- 
scribed are  the  boards  secured  together  and  sawed  off  at  the 
ends  and  along  the  curve.  To  prepare  an  elliptical  form  or 
curve  the  boards  are  placed  together  as  in  Fig.  148,  and 
upon  these  a  cross  forming  right  angles  is  placed,  and  upon 
the  strips  forming  the  cross  lines  are  drawn  intersecting  each 
other,  as  in  Fig.  148  at  C.  From  the  point  of  intersection, 
half  the  height  of  the  tunnel  is  marked  off  at  A  and  B,  also 
half  the  width  on  the  other  arms  at  D  and  E,  remembering 
that  allowance  must  be  made  for  the  thickness  of  the  shield. 
AB  now  represents  the  greater  and  DE  the  smaller 
axis  of  the  ellipse.  Half  the  smaller  axis  is  measured  off 
from  C  on  the  larger  axis  at  F  and  6r,  then  these  points 
constitute  the  foci  of  the  ellipse.  Into  these  points  nails  are 
driven.  Now  if  the  pencil,  or  scribing  point,  be  held  at  D, 
and  a  cord  or  string  passed  tightly  around  the  pencil  and 
the  two  nails,  and  tied,  then  by  moving  the  pencil  around 
either  to  the  right  or  left,  we  shall  have  the  ellipse  of  the 


PLATE  XXXI. 


Fro.  144 


FIG. 145. 


FIG.  146. 


FIG.  148. 


FIG.  149. 


To  face  page  386. 


MASONRY.  337 

Fig.  148.  The  length  of  the  axis  in  elliptical  vaults  or  tun- 
nels should  depend,  not  simply  upon  the  space  of  the  tun- 
nel, but  also  upon  the  pressure  the  walls  must  sustain. 
Should  the  main  pressure  be  from  above,  the  minor  axis  is 
shortened ;  if  the  pressure  comes  from  the  sides,  it  is  length- 
ened. But  it  should  never  be  shorter  than  the  major  axis. 

Fig.  149  represents  the  manner  of  constructing  the  egg- 
shape  pattern.  Upon  the  frame  represented  by  dotted  lines 
a  cross  forming  right  angles  is  placed,  furnished  with  lines 
as  already  mentioned ;  from  the  point  of  intersection  of  these 
lines,  (7,  half  of  the  width  of  the  tunnel  is  measured  off  to- 
ward A  and  B  and  also  toward  Z>,  and  with  this  radius  the 
lower  semicircle  A  D  B  is  described.  Through  E  and  B 
indefinite  lines  are  drawn.  Make  EC  equal  to  A  C  and 
through  ^draw  lines  of  indefinite  length,  A  ^and  B  E,  then, 
using  A  B  as  centres  with  a  radius  equal  to  the  entire  width 
of  the  tunnel,  describe  curves  A  F  and  B  G,  and  finally  with 
E  F  or  E  G  as  radius  describe  the  curve  G  F.  The  pieces 
of  the  elliptical  or  oval  forms  are  securely  nailed  together  and 
fastened  with  laths  or  strips  across  the  corners. 

For  the  construction  of  an  arched  tunnel,  a  number  of 
patterns  must  be  had  in  readiness,  but  if  the  tunnel  is  long 
the  first  used  may  be  taken  away  and  applied  for  the  con- 
tinuation as  soon  as  the  wall  is  sufficiently  dry.  The  forms 
are  placed  at  intervals  of  from  two  to  six  feet,  upon  wooden 
tressels  (as  in  Fig.  150)  or  upon  the  rock  bed.  The  long 
timbers  A  A  are  placed  upon  the  supports  S  S  of  a  frame 
in  such  a  manner  that  their  upper  faces  will  be  in  a  line 
passing  horizontally  along  the  gallery  and  against  the  wall 

22 


338  MINERALS,   MINES,   AND   MINING. 

to  bear  up  the  lower  edge  of  the  form,  and  may  be  supported 
by  tressels  as  in  Fig.  150,  or  by  posts  as  in  Fig.  151. 

After  placing  the  forms  as  above  described,  a  shield  or 
lining  is  nailed  upon  them.  (See  Fig.  152.) 

The  building  of  the  arched  wall  is  begun  by  preparing 
the  bedding.  To  give  to  this  a  proper  direction,  a  line  is 
stretched  along  the  side  of  the  gallery  and  also  one  crosswise 
in  direction  of  the  radii  of  the  arch,  and  in  accordance  with 
these  lines  the  bed  is  hewn  out.  When  the  rests,  or  bed- 
dings, are  prepared  of  masonry,  the  ground  must  be  level, 
and  the  stones  laid  level,  as  shown  in  Fig.  153.  From  both 
these  beds  the  arch  is  begun  at  the  same  time.  Upon  the 
form,  or  wooden  pattern,  stone  upon  stone  fitted  together  by 
slight  taps  of  the  hammer  are  laid,  and  when  they  come  near 
enough  to  each  other  the  wedge-shaped  keystone  is  driven 
in  by  interposing  a  piece  of  wood  between  it  and  the  ham- 
mer, lest  the  stone  be  broken  by  the  hammer.  At  the  be- 
ginning the  arched  wall  is  made  a  little  thicker  than  at  the 
top,  the  interstices  are  finally  filled  with  little  rocks,  and  the 
space  above  the  masonry  filled  in.  When  the  work  on  the 
arch  has  to  be  interrupted  before  it  is  completed,  segments 
are  wedged  apart,  as  shown  in  Fig.  154,  by  posts,  or,  if  the 
segments  are  near  each  other,  by  a  piece  of  wood,  as  in  Fig. 
155.  If  water  is  found  behind  the  wall,  then  holes  are  let 
into  the  wall  at  proper  intervals  to  draw  it  off. 

In  mines,  dry  walls  of  greater  thickness  are  preferred  to 
mortar  walls  because  the  oozing  water  dissolves  the  mortar 
and  loosens  the  walls,  whilst  in  a  dry  wall  the  water  can 
easily  run  off,  and  a  sediment  may  collect  on  the  wall  which 
may  help  to  strengthen  it. 


FIG.  150. 


FIG.  152. 


FIG.  154. 


PLATE  XXXII. 

FIG.  151. 


FIG.  153. 


FIG.  155. 


,    To  face  page  338. 


FIG.  156. 


FIG.  1/58. 


FIG.  160. 


PLATE  XXXIII. 

FIG.  157. 


Fin.  159. 


FIG. 161. 


To  face  page  338. 


MASONRY.  339 

Arched  walls  are  protected  against  water  by  putting  a 
coating  of  clay  over  them.  (Figs.  156,  157.) 

When  a  gallery  or  drift  is  to  be  arched  in,  the  nature  of 
the  arch  will  depend  upon  whether  a  partial  or  entire  arch 
is  demanded.  Should  only  the  roof  need  support,  a  short, 
low  arch  (Fig.  156),  or  a  semicircle  (Fig.  157),  is  adopted,  the 
beds  of  which  are  hewn  in  the  solid  rock.  When  the  roof 
and  one  side  only  require  protection,  and  the  lateral  pressure 
is  slight,  then  a  level  wall  is  built  upon  the  side,  and  upon 
it  a  partial  arch.  (Fig.  158.) 

When  the  pressure  is  great  upon  one  side,  a  half  vault  is 
erected.  (Fig.  159.)  Should  both  sides  and  the  roof  need 
protection,  then,  if  the  pressure  upon  the  two  sides  is  not  too 
great,  Fig.  160  represents  the  method.  If  the  pressure  upon 
the  sides  is  very  great,  Fig.  161  is  a  representation  of  the 
proper  method.  All  these  methods  presuppose  that  the 
floor  is  firm.  Should  the  floor  also  need  masonry,  it  receives 
an  oval  form,  as  in  Figs.  162,  163.  That  represented  by  Fig. 
163  is  preferred  where  much  water  is  to  be  drained  off. 

In  main  galleries,  or  adits,  it  is  customary  to  build  a 
drainage  canal  or  sluice.  Should  the  floor  be  firm,  the 
canal  assumes  the  form  in  Fig.  164.  Should  it  be  unsuitable 
for  draining,  an  inverted  arch  is  used,  as  shown  in  Fig.  165, 
or  a  close  arch  forming  a  pipe,  as  in  Fig.  166.  In  the  latter 
case  holes  are  left  at  suitable  distances  over  the  upper  side, 
so  that  the  pipe  may  be  cleared  in  case  of  stoppage.  The 
bricks  of  all  such  arches  must  be  securely  filled  in,  or  coated 
with  clay,  and  upon  them  the  tramway  is  laid.  When  water 
comes  from  the  ceiling  or  the  sides,  it  is  led  by  means  of 
pipes  through  openings  in  the  arch  into  the  canal. 


340  MINERALS,   MINES,   AND   MINING. 

The  joists  for  the  tramway,  when  these  cannot  be  let  into 
the  native  rock  in  the  sides,  are  either  walled  in,  as  in  Fig. 
167,  or  openings  are  left  at  proper  distances  for  their  recep- 
tion, leaving  larger  openings  upon  one  side  of  the  gallery 
to  provide  for  the  putting  in  of  new  joists  in  case  of  decay. 
The  floor  joists  may  also  be  placed  upon  benches,  as 
shown  in  Fig.  168,  or,  finally,  they  may  be  walled  into  the 
rubbish,  as  in  Fig.  166. 

MASONRY  FOR  SHAFTS. 

The  walling  up  of  shafts  depends,  in  its  main  features, 
upon  the  same  rules  as  the  timbering.  The  shafts,  accord- 
ing to  the  firmness  of  rock,  are  either  walled  in  entirely,  or 
only  partially. 

In  perpendicular  shafts  a  temporary  timbering  precedes 
the  masonry.  The  walls  are  built  from  below  upwards, 
and  rest,  like  a  foundation  framing,  upon  main  arches 
corresponding  to  the  long  pieces  of  a  frame  as  represented 
in  Figs.  169  and  170,  at  Z,  and  upon  shorter  arches  corre- 
sponding to  the  short  beams  of  the  foundation  frame,  as  at 
T  T,  Fig.  170. 

These  arches  are  put  at  intervals  from  two  to  four  fathoms 
according  to  the  nature  of  the  rock,  and  rest,  in  all  cases, 
upon  deep  and  sufficiently  firm  bedding.  The  main  arches 
need  a  thickness  of  from  three  to  four  feet ;  upon  them  the 
level  wall  M  is  erected.  (Fig.  169.) 

The  partition  walls  8  S  are  also  furnished  with  inserted 
arches  E  R,  Fig.  169,  which  walls  are  built  up  along  with 
the  main  walls  to  the  thickness  of  from  one-and-a-half  to 


FIG.  162. 


FIG.  164. 


FIG.  166. 


PLATE  XXXIV. 

FIG.  163. 


FIG.  165. 


FIG.  167. 


To  face  page  340. 


FIG.  168. 


PLATE  XXXV. 


FIG.  169. 


i"   I 


1,1,1.1       I       I- U-J 


FIG.  170. 


FIG.  171. 


To  face  page  340. 


MASONRY   AND    SHAFTS.  341 

two  feet.  These  partition  walls  are  also  furnished  with 
openings  into  each  other,  provided  with  frames  as  shown  in 
Fig.  130,  and  arched  over. 

In  swamp  lands,  if  shafts  are  to  be  masoned,  the  following 
method  is  used :  A  continuous  or  close  wall  is  placed  upon  a 
strong  oak  frame,  until  it  sinks  by  its  own  weight  into  the 
soft  soil.  The  inclosed  mass  is  taken  out  and  the  wall 
built  up  higher. 

The  masonry  of  inclined  shafts  or  slopes  is  very  similar  to 
that  of  galleries,  if  the  inclination  be  slight,  but  approaches 
more  to  the  masonry  of  perpendicular  shafts  if  the  inclina- 
tion be  steep.  The  partition  walls  serve  as  arch  beds  (see 
Fig.  171),  and  the  openings  into  the  galleries  are  arched  over 
as  in  perpendicular  shafts.  If  the  underlying  rock  is  firm, 
the  foundation  trenches  are  hewn  in  it  for  the  main  and  par- 
tition walls.  In  these  trenches  the  level  walls  are  founded, 
and  upon  these  the  arches  are  placed  according  to  the  num- 
ber of  the  divisions.  Should  the  underlying  rock  be  un- 
stable, then  it  is  covered  with  masonry,  and  the  other  walls 
are  placed  upon  it. 

Filling  rooms  and  other  extended  spaces,  if  they  are  to  be 
walled,  should  be  secured  by  arches;  and  the  strength  of 
such  arches  should  correspond  to  the  pressure,  and  they  must 
rest  upon  deep  and  perfectly  firm  beds. 

When  water  is  found  at  the  side  of  the  shafts  it  is  col- 
lected behind'  the  walls  and  led  through  openings  into 
pipes. 


APPENDIX. 


ARTESIAN  WELLS. 


APPARATUS  FOR  SINKING  ARTESIAN  WELLS. 

THE  derricks  used  for  sinking  wells  will  vary  in  height  with 
the  general  habits  and  ideas  of  the  workmen.  Some  of  the  deepest 
wells  have  been  dug  with  derricks  only  30  or  40  feet  in  height. 
In  the  gas  wells  of  Ohio,  Indiana,  and  elsewhere,  it  is  customary 
to  erect  derricks  60  to  70  feet  in  height,  which  in  many  cases 
are  used  only  ten  or  twelve  days,  and  then  taken  down.  Hence 
there  is  an  unnecessary  loss  of  time  and  timber. 

Mr.  W.  Blasdell,  of  Philadelphia,  who  has  been  engaged  in 
this  work  for  many  years,  writes  us  that  "the  tools  used  at  the 
present  time  I  believe  to  be  about  one-third  heavier  than  those 
enumerated  in  the  catalogues  of  Morris,  Tasker  &  Co.,  of  1874,"  but 
in  cases  where  only  trial-borings  are  made,  or  temporary  ones, 
or  those  of  no  great  depths,  about  the  same  tools  and  sizes  as 
those  of  former  use  may  be  employed. 

In  the  larger  size  derricks,  60  to  70  feet,  it  is  not  necessary  to 
use  any  heavy  timber  for  the  upper  parts.  In  many  wells,  in 
various  places,  which  have  been  worked  successfully  under  our 
own  observation,  derricks  70  feet  high  and  20  feet  spread  at  the 
base  have  been  composed  of  timber  no  larger  than  two  inches  by 
ten  inches  placed  together  on  their  long  edges,  making  one  side 
twelve  inches  wide  and  nailed  properly.  These  are  laid  up  as 
the  maker  ascends,  keeping  the  sloping  pitch  at  proper  angle 
and  bracing  with  planks  on  the  outside  as  he  goes  up.  All  the 
safety  and  strength  depend  upon  the  bracing,  generally  every 


344  APPENDIX. 

ten  feet.  The  shaking  and  trembling  of  the  derrick  on  letting 
the  drill  down  rapidly  into  the  well  never  do  any  injury  to  the 
derrick.  The  only  precaution  necessary  is  that  the  workman 
always  should  be  sure  that  the  "  up  and  down"  scantlings  rest  at 
their  ends  securely  upon  one  another,  and  that  the  foundation  is 
solid  and  perfectly  immovable  before  any  work  is  begun.  These 
derricks  are  "four  square,"-having  four-corner  inclining  posts  all 
approaching  each  other  evenly  to  the  top,  which  is  about  three 
feet  square,  and  provided  with  sufficiently  heavy  timber  to  sustain 
the  weight  of  the  rope,  drills,  and  other  apparatus,  frequently 
weighing  several  tons. 

Below  we  give  the  methods  adopted  by  Mr.  Blasdell : — 
The  derrick  used  by  myself  in  sinking  artesian  wells  through 
soil,  clays,  and  the  like,  by  boring,  is  about  33  feet  high-  by  some 
3 1  or  4  feet  wide.  It  is  often  made  of  spruce  or  pine  spars  8 
inches  at  the  butt  by  some  4J  inches  at  the  top  [hewed],  or  of 
some  light  sawed  timber  nearly  of  that  proportion.  They  are 
cross-braced  for  strength  and  slats  nailed  or  screwed  on  for 
going  up  or  down.  The  foot-piece  [opening  the  two  timbers  or 
scantling  of  this  kind  of  derrick  at  the  base]  will  be  10  feet  long, 
and  head-piece  4  feet  long,  both  mortised,  and  the  derrick  keyed 
into  them.  The  derrick  of  two  timbers  is  held  up  by  two  poles, 
or  legs,  reaching  nearly  to  the  top  of  the  derrick  and  against  two 
"chocks"  or  pieces  bolted  on  either  side  of  the  derrick,  and  then 
held  by  an  iron  strap  or  rope  lashing.  When  the  derrick  is  up 
the  distance  between  the  legs  and  the  foot-piece  of  the  derrick  is 
about  10  feet,  making  about  a  square,  thus  giving  room  to  turn 
the  yoke  or  wrench  handle  in  turning  the  auger  or  bit  on  the 
stage,  which  is  about  8  feet  above  the  ground.  To  make  the 
stage  connect  by  bolts  or  rope  lashings  place  two  scantlings  on 
either  side  about  8  feet  up  and  use  planks  for  floorings.  Douole 
gearing  is  used  for  hoisting  with  a  6-inch  pinion-wheel  and  24- 
inch  cog-wheel,  with  a  9-inch  wooden  drum  on  the  shaft  of  the 
cog-wheel  for  the  hoisting  rope.  A  single  4J-inch  rope  is  used 
for  the  hoisting  fall  attached  to  the  wooden  drum  then  up  and 
passing  through  the  iron  «  gin-wheel"  or  pulley  at  the  head  of 
the, derrick,  then  down  to  the  rods  or  augers.  Attached  to  the 


SINKING   ARTESIAN   WELLS.  345 

fall  is  an  iron  "  swivel-hook"  made  flat  so  as  to  hook  in  the  eye 
of  the  rods  or  augers,  for  hoisting  them ;  the  socket,  as  seen  in 
some  catalogues  (No.  49,  of  Morris,  Tasker  &  Co.,  10th  edition),  is 
not  used  by  some  workers.  The  fall  and  hook  are  used  for  hoist- 
ing the  levers  to  shove  the  pipe  [or  tubing] — not  using  the  small 
derrick  as  sometimes  depicted.  The  bearings  and  shaft  of  the 
pinion-wheel  should  be  on  the  same  side  of  the  derrick  that  the 
drum  or  cog-wheel  shaft  is,  and  the  crank  on  the  upper  or 
pinion-wheel  shaft.  There  is  an  error  in  the  drawing  in  this 
respect  in  one  of  the  catalogues  most  extensively  circulated. 

The  pipes,  or  tubing,  generally  used  in  sinking  artesian  wells 
are  sometimes  of  cast-iron,  and  may  be  as  large  as  8, 12,  and  even 
20  inches  calibre,  in  sections  of  8  and  10  feet,  connected  together 
with  wrought-iron  bands  heated  and  shrunk  on.  The  metal  of 
the  pipe  is  thickened  at  the  joint,  making  the  calibre  a  little 
smaller,  then  the  outside  of  the  pipe  is  turned  down  in  a  lathe 
so  as  to  make  the  band  flush  with  the  outside  of  the  pipe  after  it 
is  shrunk  on.  The  end  turned  down  on  the  pipe  is  from  3  to  4 
inches  in  length  and  depth  to  correspond  with  the  thickness  of 
the  band,  which  is  usually  from  J  inch  to  f  inch  thick.  The 
ends  of  the  pipe  butt  together,  one  resting  on  the  other ;  the  bands 
should  be  a  little  narrower  than  the  turned  ends  of  the  pipe,  so 
that  the  pipes  will  closely  rest  together. 

TO  connect  the  pipes  together  in  boring  an  artesian  well,  flrst 
shove  the  pipe  down  as  far  as  the  levers  will  carry  it,  which 
will  leave  it  above  ground  some  2  or  3  feet,  then  sling  the 
pipe  that  you  wish  to  connect  and  raise  with  the  fall  and  let  it 
hang  immediately  over  the  lower  pipe.  The  band  must  now  be 
heated  red  hot  in  a  sheet-iron  furnace,  with  a  wood  fire  (or  in 
any  similar  way),  and  with  a  pair  of  tongs  place  the  band 
on  the  first  pipe,  then  lower  the  other  pipe  into  the  band,  and 
when  the  band  cools  it  will  contract  and  make  a  tight  joint.  The 
band  when  cold  should  be  a  little  smaller  than  the  turned  ends 
of  the  pipe ;  the  heating  expands  the  band,  which  should  be  put 
on  the  pipe  quickly  in  order  to  success.  The  first,  or  bottom 
pipe,  has  a  sharp  iron  or  steel  cutting  band  on  the  lower  end  to 
cut  its  way  down  as  the  boring  is  done  through  the  inside  of  the 


346  APPENDIX. 

pipe.  In  some  cases  the  reamer,  or  combination  auger,  is  used  to 
enlarge  the  hole  as  in  very  stiff  clays. 

The  u  twist"  or  "  spiral  auger"  is  found  to  work  better  than 
any  other.  Four  to  6  twists  are  commonly  used  in  the  full 
length,  5  feet,  made  of  1J  inch  iron  steel  pointed,  or  of  all  steel  one 
inch  square. 

Rods  used  are  in  15  feet  sections,  1J  inches  square.  Iron  with 
male  and  female  socket  joints,  held  with  a  key  and  a  clasp,  to 
cover  and  hold  the  key  in  its  place. 

The  sand  pump  is  made  of  sheet  iron  from  2  to  3  feet  in  length 
of  a  size  loosely  to  fit  inside  the  pipe ;  it  is  furnished  with  a  single 
leather  valve  at  the  lower  end,  hinged  and  resting  on  an  iron  ring 
|  to  }  of  an  inch  thick  as  a  base.  This  ring  is  from  1  to  2  inches 
deep,  beveled  thin  at  the  lower  edge  and  riveted  in  the  lower  end 
of  the  sand  pump.  The  leather  valve  is  strengthened  by  thin 
iron  plates  riveted  on  either  side  of  it.  The  pump  is  used  for 
pumping  sand  and  gravel,  and  sometimes  stone  can  be  pumped  up 
of  a  size  as  large  as  the  pump  will  admit.  To  use  the  pump,  attach 
a  single  line  to  the  bail  and  lower  it  into  the  well  pipe  to  the 
bottom ;  then  slowly  draw  it  up  some  12  or  16  inches,  arid  let  it 
drop  quickly.  Keep  repeating  until  it  is  well  charged,  then  draw 
up  and  empty. 

The  pump  being  nearly  as  large  as  the  calibre  of  the  artesian 
pipe,  the  drawing  it  up  in  the  wrater  forms  a  vacuum  and  the  sand 
and  debris  follow  the  pump  up  and  by  dropping  the  pump  quickly 
the  valve  opens  inside,  and  the  pump  being  heavier  than  the 
floating  material  drops  quicker  and  shuts  over  it,  and  by  raising 
the  pump  the  valve  closes  and  retains  a  portion  each  time. 

There  must  be  water  in  the  well  to  cover  the  sand-pump,  in 
order  that  it  shall  work.  If  the  well  will  not  afford  the  water, 
it  can  be  turned  in.  A  single  "  gin  wheel"  or  pulley-block  is 
used  at  the  head  of  the  derrick  for  the  sand  pump  rope. 

In  boring  or  sinking  tubing  or  pipe,  the  work  is  generally  done 
by  man-power.  To  turn  the  auger  a  lever,  or  yoke  of  iron,  some 
4  feet  long,  is  attached  to  the  rods  by  a  u  set-screw"  and  turned 
by  two  or  three  men  working  on  the  elevated  stage.  When  the 
auger  is  full,  draw  up,  and  disconnect  the  rack  rod  at  the  joint. 


SINKING    ARTESIAN   WELLS.  347 

In  order  to  hold  the  rods  while  disconnecting  them,  let  the 
shoulders  near  the  end  of  the  rod  (male  end)  rest  on  the  crotch 
bar  (or  fork,  STo.  33,  M.,  T.  &  Co.'s  cat.,  10th  ed.),  which  is  placed 
on  and  held  up  by  the  stage,  or  in  case  the  pipe  should  be  higher 
than  the  stage  then  let  the  fork  rest  on  the  top  of  the  pipe. 

Levers  used  to  force  the  pipe  down  are  usually  about  20  feet 
in  length,  1  foot  in  diameter,  of  round,  or  square  timber.  In  the 
center  of  them  15  inches  from  the  end  there  is  a  slot  1J  inches 
wide,  9  inches  in  length  at  the  top,  and  4  inches  at  the  bottom, 
cut  through  them  for  the  lever  irons  to  work  in. 

o 

The  lever  iron  is  17  inches  in  length,  4  inches  wide,  and  1  inch 
thick.  At  the  top  end  there  is  a  round  hole  1J  inches  for  a 
shackle  pin,  so  as  to  connect  and  shackle  it  to  the  side  chains  to 
draw  or  force  the  pipe  down.  At  the  lower  end  there  is  a  square 
and  deep  hole  for  a  key  to  hold  it,  that  it  may  not  pull  through 
the  slot  in  the  levers.  By  cutting  the  slot  on  the  top  of  the  lever 
it  will  admit  raising  the  lever  to  an  angle  sufficient  to  shove  the 
pipe.  One  foot  from  the  end  of  the  lever  it  is  necessary  to  have 
a  pin  projecting  up  some  6  inches  to  prevent  the  lever  slipping 
under  the  fulcrum  stick  when  the  former  is  raised  up  to  shove 
the  pipe.  The  two  fulcrum  chains  should  each  be  about  17  feet 
in  length,  and  made  of  iron  f  inch  in  diameter.  The  two  side 
chains  should  be  12  feet  long,  each  made  of  1J  inch  iron  and 
the  link  5  or  6  inches  in  length  to  admit  of  a  heavy  shackle  to 
attach  them  to  the  lever  irons.  The  bottom,  or  lower  fulcrum 
stick,  should  be  10  or  12  feet  in  length,  by  some  12  or  14  inches 
on  the  face,  and  8  or  10  inches  thick ;  a  wide  faced  one  is  better 
for  holding.  The  top  fulcrum  should  be  round,  of  some  10  inches 
in  diameter  and  6  feet  in  length.  In  the  "  combination  auger," 
there  are  two  steel  cutters  screwed  on  the  bottom  plate.  So  by 
turning  the  auger  ahead  they  will  open  and  cut  larger  than  the 
pipe,  and  by  turning  back  they  close  up  so  that  it  can  be  withdrawn. 

Valve  sockets,  or  "  catchalls,"  are  to  catch  the  rods,  when  by 
accident  they  become  disconnected.  Steel  dogs,  of  different 
sizes,  are  hinged  to  them  which  will  catch  by  drawing  up  and 
hold  the  rod. 

The  "  catchall"  for  hauling  pipe  has  a  dog,  a  little  longer  than 


348  APPENDIX. 

the  calibre  of  the  pipe,  hinged  to  the  main  stem.  So,  that  when 
drawing  up,  the  heel  slips  a  little  and  the  point  being  steel  and 
sharp  catches  and  thus  holds  the  pipe  to  draw  it  out.  Some- 
times the  connecting  bands  adhere  fast  enough  to  draw  the  pipe 
with  chains  made  fast  to  the  top  pipe. 

The  "  wrench  bar"  is  used  temporarily  to  turn  the  rods  in 
boring  instead  of  using  the  wrench  handle. 

The  "  boulder-cracker"  is  raised  with  a  rope  and  dropped  to 
break  stone,  but  it  is  not  very  effective.  A  pointed  chisel  made 
to  connect  the  rods  and  all  raised  and  dropped  together  is  prefer- 
able. 

The  "  spring  catch"  for  hauling  pipe,  also  "  hooks,"  are  seldom 
used,  nor  is  the  "  lifter." 

A  line  should  be  attached  to  the  "catchall,"  to  regulate  and 
prevent  catching  where  not  wanted. 

TO  COMMENCE   AN  ARTESIAN  WELL. 

Put  the  derrick  up,  then  commence  in  front  4  feet  from  the 
base  of  the  derrick  parallel  with  the  plane  of  the  derrick  legs, 
and  dig  a  trench  18  inches  wide,  10  feet  long  and  5  feet  deep  for 
the  bottom  fulcrum  stick.  Then  lower  the  centre,  or  bight,  of 
the  two  fulcrum  chains  in  the  trench  some  4  feet  apart,  allowing 
the  two  ends  of  each  chain  to  extend  a  few  feet  above  the  surface 
of  the  ground,  then  place  the  fulcrum  stick  in  the  trench  on  top 
of  the  chains  and  secure  it  by  placing  cross  pieces  of  plank  or 
small  timber,  allowing  each  end  to  penetrate  the  earth  on  the 
sides  of  the  trench  for  holding.  Then  fill  the  trench  up  on  top 
of  ^the  stick  with  the  earth  which  was  excavated,  and  tamp  all 
solidly,  thus  securing  the  stick  for  leverage  power  in  shoving  the 
pipe  down.  We  next  place  two  blocks  of  timber  (immediately 
over  the  filled  up  trench),  some  five  feet  apart,  and  lay  the  top 
fulcrum  stick  on  the  blocks,  and  secure  by  passing  the  ends  of 
the  fulcrum  chains  over  it,  and  shackling  together.  Thus  a  com- 
plete fulcrum  power  may  be  obtained  for  the  levers  in  shoving,  or 
forcing,  the  pipe  into  the  earth.  The  pipe  is  then  placed  imme- 
diately in  front  of  the  centre  of  the  fulcrum  sticks,  and  the  boring 
commenced  through  the  inside  calibre  of  the  pipe,  and  continued 
from  one  to  two  feet  below  the  bottom  of  the  pipe ;  then  the 


SINKING   ARTESIAN   WELLS.  349 

shoving  band  is  placed  on  the  pipe.  The  shoving  chains,  or  side 
chains,  hung  on  the  side  hooks  which  are  attached  to  the  shoving 
band  on  either  side,  and  the  ends  of  the  levers  are  placed  under 
the  top  fulcrum  stick,  one  on  either  side  of  the  pipe.  The  oppo- 
site ends  are  now  raised  up,  by  the  derrick,  some  seven  or  eight 
feet  in  height,  and  the  side  chains  shackled  to  the  lever  irons, 
when  one  link,  or  five  or  six  inches  are  gained  at  each  time  of 
raising  the  levers,  and  thus  the  pipe  is  drawn,  or  forced,  down 
into  the  earth.  If  there  is  too  much  friction  resistance  against 
the  pipe  for  the  weight  of  the  levers  to  force  it  down,  weights 
must  be  applied  to  the  ends  of  the  levers,  which  will  give  a 
power  of  some  fifteen  tons  pressure.  In  boring  through  clay, 
loam,  or  marl,  only  use  the  spiral  auger,  which  adheres  to  it  and 
when  full  it  may  be  drawn  up  and  cleaned.  In  drawing  the 
auger  up  the  rods  have  to  be  disconnected  at  the  joints  one  at  a 
time. 

When  sand,  gravel,  or  small  stone  is  reached  the  sand  pump 
is  used  to  take  it  out,  keeping  the  leverage  power  on  at  the 
same  time  to  force  the  pipe  down.  When  stone,  or  large  boul- 
ders are  encountered,  it  is  found  very  difficult  and  sometimes  im- 
possible to  shove  the  pipe.  In  such  cases  it  is  customary  to  use 
a  heavy  drill,  or  boulder-cracker,  as  it  is  called,  and  try  to  break 
or  displace  them.  Soft  stone,  such  as  slate,  or  sandstone,  can 
be  broken,  but  if  there  is  a  hard  stone  which  is  almost  or  actually 
impossible  to  break,  then  the  well  digging  has  to  stop,  and  the 
pipe  drawn  and  changed  to  some  other  point. 

Sometimes  a  boulder-catcher,  or  "lazy  tongs,"  can  be  used  to 
advantage  in  picking  up  stone,  or  boulders. 

A  larger  supply,  and  better  water,  are  usually  obtained  after 
passing  through  good  pure  clay.  In  all  cases  in  order  to  obtain 
a  supply  of  water  it  is  necessary  to  reach  a  water  bearing  stratum 
of  coarse  sand,  gravel,  pebbles,  or  a  bed  of  small  stone,  or  boulders, 
which  are  generally  intermixed  more  or  less  with  sand  or  gravel. 
It  is  necessary  to  carry  the  pipe  a  few  feet  into*  the  water-bearing 
stratum,  in  order  that  the  water  shall  not  be  interfered  with 
from  washings  of  the  above  clay  stratum.  It  is  very  seldom  that 
a  supply  of  water  can  be  obtained  in  fine  sand,  for  the  simple 


$50  APPENDIX. 

reason  that  pumping  the  head  of  water  down  will  cause  the  sand 
to  rise  in  the  pipe  with  the  water,  and  very  quickly  choke  off 
the  supply. 

Most  of  the  wells  in  the  vicinity  of  Philadelphia  are  through 
soil  and  the  water  ohtained  in  a  gravel  stratum  ;  patent  flush  pipes, 
or  those  which  have  no  ridge  on  the  outside,  are  used  of  8,  12, 
and  20  inches  calibre.  In  some  cases  where  water  is  not  obtained 
and  the  rock  reached,  a  drill  is  used  cutting  a  hole  from  4  to  12 
inches  calibre,  and  the  water  is  obtained  from  the  fissures  and 
crevices. 

Sometimes  the  common  mining  tools,  spring-pole  and  man- 
power, may  be  employed  in  drilling  the  rock,  and  sometimes  the 
oil  well  tools,  with  walking-beam  and  steam  power,  must  be  re- 
sorted to. 

In  using  the  spring-pole  for  mining  purposes,  or  shallow  wells, 
for  water,  sometimes  the  solid  iron  rods  with  screw  joint  are 
sufficient,  and  sometimes  extra  heavy  IJ-inch  gas  pipe  rods,  and 
sometimes  wooden  rods  with  strap  screw  joints.  In  most  of  the 
salt  wells  which  were  drilled  in  former  times,  and  some  which  went 
down  several  hundred,  or  a  thousand  feet,  the  spring-pole  with 
wooden  rods  and  strap  points  was  successfully  employed. 


OIL  AKD  GAS  WELLS. 

To  sink  an  oil  or  gas  well  it  is  necessary  to  have  a  steam-en- 
gine from  8  to  12  horse  power,  a  derrick  45  feet  high,  with  a  base  of 
15  feet,  with  a  "  sampson  post"  8  or  10  feet  high  for  the  walking- 
beam,  which  must  be  20  to  30  feet  in  length,  and  other  tools  and 
fixtures  as  enumerated  in  the  usual  catalogues  of  such  machinery. 

To  start  a  well  where  the  soil  overlies  the  rock,  either  the 
plan  already  described  must  be  used,  or  a  heavy  cast-iron  driving 
pipe  of  5  or  6  inches  calibre  is  driven  to  the  rock  by  raising  a 
heavy  timber  (some  14  inches  square  by  12  or  14  feet  in  length) 
to  the  head  of  the  derrick  and  letting  it  drop  upon  an  iron  cap 
placed  on  the  top  of  the  pipe.  The  drill  is  also  used  to  cut  up 
the  soil,  or  any  obstructions  which  may  be  encountered,  and  the 


OIL   AND   GAS   WELLS.  351 

sand  pump  to  take  the  debris  out.  Where  the  rock  crops  to  the 
surface  no  pipe  is  required. 

To  commence  drilling  first  connect  the  "  auger  stem"  to  the 
"  centre-bit,"  then  the  "  jars"  to  the  auger  stem,  then  the  "  sinker 
bar"  to  the  jars,  then  the  rope  socket  to  the  sinker  bar,  then  at- 
tach the  drilling  rope  to  the  rope  socket,  then  clasp  the  temper 
screw  to  the  rope  at  the  point  where  required,  then  attach  the 
temper  screw  to  the  walking-beam.  The  screw  is  about  3  feet 
or  more  in  length,  and  in  starting  should  be  closely  screwed  up 
and  held  with  a  set  screw,  and  as  the  drill  cuts  its  way  down  to 
be  gradually  unscrewed  to  the  end. 

After  about  3  feet  are  drilled  the  centre-bit  is  withdrawn,  the 
sand  pump  put  in,  and  the  debris  pumped  out,  then  "the  reamer" 
which  is  about  1  inch  larger  than  the  centre-bit  is  put  in  and  the 
hole  reamed  down  as  far  as  the  centre-bit  has  cut. 

The  reamer  makes  the  hole  round  and  smooth.  Where  the 
centre-bit  is  used  (without  reaming)  for  any  great  distance  the 
hole  becomes  triangular  in  shape.  Generally  the  rock  operated 
in  for  oil  is  slate,  shale,  and  limestone  or  sandstone.  After  a 
well  is  drilled  it  is  then  cased  with  wrought-iron  tube,  or  casing, 
with  a  seed-bag  attached  to  it  to  shut  off  water-veins. 

To  "seed-bag"  the  casing  of  a  well,  a  leather  case  like  a  boot- 
leg, some  3  feet  in  length,  is  slipped  over  the  iron  casing  and 
tied  at  the  lower  end  with  a  string.  Then  the  space  between  the 
leather  case  and  iron  casing  is  filled  with  flax-seed  and  the  top 
end  of  the  leather  case  is  securely  tied  with  a  hemp  cord. 

The  leather  case,  or  seed-bag,  is  somewhat  larger  than  the  iron 
casing,  so  that  when  filled  with  the  seed  it  will  nearly  fill  the 
drill-hole,  a  gauge  being  passed  over  it,  the  size  of  the  drill-hole, 
to  make  it  smooth  and  parallel.  When  the  seeds  swell  in  the 
water  it  will  make  the  space  between  the  well  and  casing  water- 
tight, thus  excluding  the  water-veins  from  the  oil-veins  while 
pumping  or  flowing. 

The  seed-bag  is  put  on  the  casing  so  that  when  put  down  into 
the  well  it  will  be  immediately  above  the  oil-vein. 

In  drawing  the  casing  the  top  string  on  the  bag  breaks  and  the 
bag  turns  inside  out,  discharging  the  seed. 


352  APPENDIX. 

Formerly  the  wells  drilled  were  from  4  to  5  inches  diameter,  but 
many  are  from  6  to  8  inches. 

It  is  probable  that  the  most  of  the  oil  obtained  at  the  present 
day  is  after  passing  the  third  or  fourth  sand  rock,  formerly 
obtained  under  the  second  sand. 

While  the  drill  is  in  operation  a  man  turns  the  rope  to  which 
the  tools  are  attached  forwards  several  times  then  backwards  in 
order  to  drill  a  round  hole.* 

*  For  drawings  of  a  complete  oil-well  derrick  or  carpenter's  rig  see  Crew 
A  Practical  Treatise  on  Petroleum,  Philadelphia,  Henry  Carey  Baird  &  Co., 
1887. 


INDEX. 


A  CETATE    of   ammonium,    symbol 
Xl.  and  atomic  weight,  59 

test  of,  59 
of    sodium,    symbol   and   atomic 

weight,  58 
test  of,  58 
Acetic  acid,  symbol  and  atomic  weight 

of,  52 
test  for,  52 

Africa,  diamond  fields  of,  251 
Alcohol,  its  uses  in  chemical  work,  44 
Alkaline  earths,  42 
Alumina,  employment  in  fluxes,  54 
symbol  and  atomic  weight,  54 
Ammonia,  preparation  and  test  of,  54 

symbol  and  atomic  weight,  54 
Ammonium,    chloride,    hydrosulphide, 

molybdate,  and  acetate  of,  59 
oxalate,  and  neutral  succinate  of,  60 
Analysis  of  the  ore  of  platinum,  table 

of,  215 

Analytical  scales,  requirements  of,  67 
Antimonial  silver,  description  of,  114, 

115 

Antimony,  227,  232 
assay,  caution,  232 
characteristics  of,  227 
estimation  of,  230,  231 
gravity,  227 
hardness,  227 
localities  of,  227 
Makins's    method    of    estimating, 

231,  232 

melting  point,  227 
native,  associations  of,  227 
to  distinguish,  from  bismuth,  231 
uses  of,  230 
Apparatus,  chemical,  list  of,  71-79 

for  rapid  filtering,  illustrated  and 

described,  75-77 

for  sinking  artesian  wells,  343-348 
Aqua  regia,  composition  of,  50 
23 


Arched  masonry,  forms  generally  used, 
illustrated  and  described, 
334,  335 

where  needed,  334 
tunnel,  construction  of,  337,  338 
wall,  construction  of,  338 
walls,    to    protect,    against  water, 

illustrated  and  described,  339 
Arch,  to  give  it  the  proper  form,  335- 

337 

Argentite,  characteristics  of,  115,  116 
Arsenical  iron,  113 
Artesian  well,   to  commence  an,  348, 

349 

wells  in  the  vicinity  of  Philadel- 
phia, 350 
removal   of    obstructions   met 

with  in  boring,  349,  350 
sinking,  343-350 
Assay  furnace,  illustrated  and  described, 

64-67 

Assays,  testing  the  alkaline  or  acid  con- 
dition of,  155,  156 
Assorting  the  ore  in  the  mine,  300 
Atomic  weights,  practical  use  of  table 
of,  39-42 


BARIUM,  chloride,  nitrate,  and  car- 
bonate of,  60 
Barytes,  appearances  of,  22 

to  distinguish,  from  lime  carbonate, 

22 
Beds,  ore,  with  inclination  less  than  40 

degrees,  working,  287-291 
Bismuth,  232-234 
brittleness,  232 
crystallization,  232 
detection  of,  233 
effects  of  acids  upon,  233 
flamability,  233 
fusing  point,  233 


354 


INDEX. 


Bismuth — 

gravity,  232 
hardness,  232 
lustre,  232 
malleability,  232 

metallic,  uses  of,  for  alloys,  amal- 
gams, etc.,  234 
occurrence,  232 

in  the  United  States,  234 
silver,  description  of,  115 
streak  and  color,  232 
to  distinguish  it  from  lead,  233,  234 
under  the  blowpipe,  234 
Black  flux,  components  of,  55,  56 
Blende,  185-187 

under  the  blowpipe,  185,  186 
Blowpipe,  hints  for  students,  29,  30 
inner  and  outer  flames  of,  27 
philosophy  of  its  action,  27 
practice,  materials  for,  28,  29 
review  of,  35-37 
with  lead  oxide  and  carbonate 

of  soda,  30 

with  metallic  zinc,  30-36 
preparatory     practice     with     the, 

29-35 
the,  27-35 
Blowpipes,  requisite  characteristics  of, 

27 
requisites   in   a  practitioner  with, 

27 
Borax  bead  in  powdered  charcoal,  31 

in  oxide  of  manganese,  31,  32 
composition  of,  58 
Boring   a   well,    the    power   generally 

used,  346 

Boulder  cracker,  use  of,  348 
Brake  attachment,  illustrated  and  de- 
scribed, 307,  308 
Brasque,  explanation  of,  77,  78 
Breast,  when  it  reaches  the  wall,  treat- 
ment of,  286 
Bromine     and     iodine,     symbols     and 

atomic  weights 'of,  46 
uses  of,  46 

chemical  action  of,  47 
preparation  of,  47,  48 
three  forms  of,  46,  47 
Brown  hematite,  characteristics  of,  140, 

141 

general  impurities  of,  141 
geological  position  of,  141 
peculiarities  of  appearance  in 

some  mines,  141,  142 
Buckets,  to  balance,  illustrated  and  de- 
scribed, 308,  309 


Buddling,  description  of,  298 

employed  in  steep  mountain  val- 
leys, 298,  299 
with  a  hose,  299 
Buhr  stones,  245,  246 

commercial  statistics  of,  246 
principal  localities  of,  in  the 

United  States,  245,  246 
substitution  of  rollers  for,  246 
uses  of,  246 

Bulk  of  a  body,  a  mode  of  determining, 
22,  23 


/"CADMIUM  and  bismuth  compounds, 
\J     to  separate  silver  from,  124 
Calamine,  English  manner  of  distilling, 

187,  188 

Calcium,  chloride  of,  61 
Carat,  the  weight  of,  246,  247 
Carbonate,  lime,  description  of,  18 
of  barium,  preparation  of,  60,  61 

symbol  and  atomic  weight,  60 
of  potassium,  symbol  and  atomic 

weight,  55 
test  of,  55 
of    sodium,     symbol    and    atomic 

weiirht,  58 
test  of,  58 
of    zinc,     characteristics    of,    and 

where  found,  185 
under  the  blowpipe,  186 
Carbonic  acid  gas,  symbol  and  atomic 

weight  of,  53 

dioxide  (carbonic  acid  gas),  prepa- 
ration of,  53 

symbol  and  atomic  weight  of, 

53 

Car,  loaded,  to  prevent  a,  from  "jump- 
ing the  track,"  307 
Carpentry,  mining,  318-324 
Cassiterite,  176 

"Catchall,"  equipment  of,  347,  348 
Caution    in    decomposing   copper   sul- 
phides, 130,  131 
in  regard  to  copper  solution,  128, 

129 

in  working  silver  with  lead,  121 
to   the   inexperienced   operator  in 

using  reagents,  69 
Cautions  and  suggestions  in  analysis  and 

assaying,  63-68 
in  making  the  dry  assay  of  iron, 

144,  145 

Charcoal,  preparation  of,  for  use  under 
the  blowpipe,  27,  28 


INDEX. 


355 


Chemical  analysis,  certain  principles  of, 

36j  37 
importance  of,  in  mineralogy, 

17,  18 

apparatus,  list  of,  71-79 
symbols,  table  of,  37,  38 
Chemicals  for  private  laboratory,  72,  73 
Chemistry,  value  of,  in  mineralogy,  1  7 
Chlorate    of    potassium,     symbol    and 

atomic  weight,  56 
Chloride   of    ammonium,    symbol    and 

atomic  weight,  59 
test  of,  59 
of  barium,  test  of,  60 

symbol  and  atomic  weight,  60 
of  calcium,  preparation  of,  61 

symbol  and  atomic  weight,  61 
of  nickel,  way  of  obtaining,  133 
of    sodium,     symbol    and    atomic 

weight,  57 
test  of,  57 
•       use  of,  57 

Chlorine,    process    of    obtaining,    illus- 
trated and  described,  45,  46 
symbol  and  atomic  weight,  45 
use  of,  46 
Chlorite,  a  good  sign  in  searching  for 

corundum,  242 
Chrome  iron,  components  of,  235 

ore,   quantitative   analysis  of, 

237 

Chromite,  constituents  of,  235 
Chromium,  235-238 

before  the  blowpipe,  235 

brittleness  of,  235 

color,  235 

decomposition  of  the  ore,  236 

first  notice  of  its  occurrence  in  the 

commercial  way,  236 
gravity,  235 
hardness,  235 
its  occurrence  in  the  United  States, 

236 

lustre,  235 
solubility  of,  236 
streak,  235 

Cinnabar,  characteristics  of,   221 
Cleavage  of  minerals,  20 
Coal-beds,  cutting  levels  and  drifts  in, 
illustrated     and    described, 
290,  291 

of  different  benches,  working, 
illustrated  and  described, 
291 

the  slope  in,  illustrated  and 
described,  268 


Coal- 
mines, precautionary  rules  to  pre- 
vent    spontaneous     combustion, 
292 

Cobalt,  238-240 
color  of,  239 
compounds,  detection  of,  under  the 

blowpipe,  239 
fusibility,  239 
glance,  238 
gravity,  239 

inability  to  plate  with,  239 
metallic,  nominal  value,  239 
minerals,  localities  of,  239 
only  present  use  of,  239 
ores  of,  238 
preparation  of,  from  the  ore,  238, 

239 

separation  of,  from  nickel,  240 
Cocalico,  246 
Color,    importance   of,   in   determining 

the  nature  of  a  substance,  20,  21 
Combining  weights  of  elementary  bodies, 

table  of,  38,  39 
Compounds,  groups  of,  42,  43 
Connecting  the  pipes  in  boring  an  arte- 
sian well,  345 
Copper,  125-131 

assay  by  the  dry  method,  127,  128 

by  the  wet  method,  128 
associations  with,  126 
blowpipe  and  other  modes  of  detec- 
tion of,  127 
compound  ores  of,  126 
hardness  and  gravity,  126 
its  geological  position,  126 
minerals,  three  classes  of,  125 
native,  geographical  localities  of,  in 

the  United  States,  125 
ores,  silver  contained  in,  114 
oxide  of,  symbol  and  atomic  weight 

of,  55 

pyrites,  characteristics  of,  126 
separation  of  silver  from,  122 
solution,  caution  in  regard  to,  128, 

129 
sulphides,  caution  in  decomposing, 

130,  131 

sulphides,  decomposition  of,  129 
Corundum  and  emery,  241-243 
associations  of,   241 
gravity,  241 
hardness,  241 
in    its     purest     crystalline     state, 

colors  of,  241 
lustre,  241 


356 


INDEX. 


Corundum — 

sample,  to  test  its  abrasive  power, 

242,  243 

under  the  blowpipe,  241 
uses  of,  242 

Crucibles,  platinum,  requirements  of,  77 
Crystal  forms,  use  of,  for  the  mineralo- 
gist, 36 
Crystallization,  immense  importance  of, 

to  the  mineralogist,  18,  19 
Crystals,  three-sided  and  six-sided,  19 
Cupel,  description  of,  34 
Cupellation,  knowledge  of  the  process 

necessary  to  the  mineralogist,  33,  34 
Cupellation  of  ores,  120,  121 

DAY  shaft,  intention  of  a,  265 
Day  working,  296-300 
Deposit,  barren  rock  met  in  a,  treat- 
ment of,  illustrated  and  described, 
287 

discovered  by  a  tunnel  which  has 
entered  the  ore,  working  of  a, 
illustrated  and  described,  292, 
293 

greatly  inclined,  opening  of  a,  274 

nearly  horizontal,  opening  of  a, 
274,  275 

opening  a,  when  the  mountain  is 
steep  and  the  strike  of  vein  is 
parallel  to  it,  274 

opening  a,  when  the  strike  of  the 
vein  is  across  the  strike  of  the 
mountain  ridge,  274 

striking  under  a  plain,  opening  of 

a,  illustrated  and  described,  274 
Deposits  and  beds,  stratified,  prepara- 
tion and  working  of,  287-292 

large  irregular,  opening  of,  275 

large,  possessing  some  degree  of 
regularity,  working  of,  292 

with  little  or  no  regularity  of  form, 
general  rule  in  regard  to  minhxr 
of,  292 

with  little  or  no  regularity  of  form, 
preparation  of,  for  mining,  illus- 
trated and  described,  292-294 
Derrick  used  by  Mr.  Blasdell,  344,  345 
Derricks  used  in  sinking  wells,  343-345 
Diamond,  appearance  of,   in  the  routrh 
state,  250 

bi-Nt  test  for,  250 

debris  ,in  North  Carolina,  Dr. 
Genth'0  opinion  of,  247 

fields  of  Africa,  251 


Diamond — 

gravity,  248 

localities  where  found  in  the  United 

States,  246,  249 
the,  246-251 

Diamonds,  their  ability  to  scratch  glass 
no  proof  of  their  distinctive  value, 
250 

Distilled  water,  use  of,  in  accurate  de- 
termination of  specific  gravity,  24,  25 

Distilling  zinc,  apparatus  for,  illustrated 
and  described,  187-189 

Ditches  in  buddling,  substitute  for,  299 

Drainage  of  a  mine,  258,  259 

Drift  gallery,  opening  from  another  and 
timbered  gallery,  illustrated  and  de- 
scribed, 323 

Drifts,  explanation  of  the  term,  260 

Dry  assay  of  iron,  143,  144 

Dump  carts,  illustrated  and  described, 
315,  316 

Dumping  floor,  depth  and  width  of, 
269,  270 

Dyscracite,  description  of,  114,  115 


TJ1CONOMIC  treatment  and  history  of 
Lj     the  useful  minerals,  81-251 
Egg-shaped   arch,    illustrated    and   de- 
scribed, 337 
Elementary  bodies,  table  of  combining 

weights  of,  38 

Elements  of  material  substances,  36,  37 
Elliptical  arch,  illustrated  and  described, 

336,  337 

Emery,  commercial  statistics  of,  243 
occurrence  of,  in  the  United  States, 

241,  242 

Esopus  stone,  245,  246 
Excavations,  protecting  the,  258 
Excavation  through  insecure  rock,  tim- 
bering for,  illustrated  and  described, 
325 

Exhaustion  of  iron  ore  deposits  of  the 
United  States,  173,  174 


J71ERROMANGANESE,  208 
JU       Filtering,  rapid,  apparatus  for,  il- 
lustrated and  -described,  75-77 
Filter  papers,  folding  of,  7S-75 

treatment  of,  67 
Folding  filter  papers,  73-75 
Fracture  of  minerals,  20 
Framing,  method  of,  illustrated  and  de- 
scribed, 321 


INDEX. 


357 


Freieslebenite,  characteristics  of,  115 
Fuming  nitric  acid,  use  and  preparation 
of,  78,  79 


/^ALENA,  description  of,  196 
\JC         only  abundant  lead  ore,  194 
Galleries,  names  of  the,  in  mines,  264 

vertical  distances  between,  264 
Gallery,   arching  of  a,  illustrated  and 

described,  339 
construction  of  drainage,  canal  or 

sluice,  illustrated,  339 
entirely  within  the  lode,  illustrated 

and  described,  261,  262 
floors,  descent  of,  259 
floor,  to  prepare  for  transportation 
and  drainage,  illustrated  and  de- 
scribed, 323,  324 

opening  a,  from  the  side  of  a  hill, 
illustrated  and  described,  260- 
262 

parallel  to  the  "pay  rock,"  illus- 
trated arid  described,  262 

in  the  rock  and  partly  in  the 
lode,  illustrated  and  described, 
261 

second  story,  opening  of  a,   illus- 
trated and  described,  286,  287 
walls,  masonry  of,  332,  333 
when  the  rock  is  not  in  horizontal 
strata,  illustrated  and  described, 
261.  262 

Gas  and  oil  wells,  350-352 
Geology   of  gold  and   its  associations, 

88-96 

Gersdorffite,  composition  and  character- 
istics of,  132,  133 
Glass  of  borax,  use  of,  58 
Glassware   and   reagents,   how  to  use, 

68-71 

heating,  69,  70 
Gold,  83-110 

absurd  deduction  of  French  chem- 
ist in  regard  to,  93 
alloying  metal,  93 
alloys,  methods  of  treating,  96-100 
treatment   of    in   the    United 

States  Mint,  96 
and  its  associations,  geology  of,  88 

-96 
and  platinum,  to  separate  from  the 

slag,  98,  99 
average     fineness    of,     in    several 

States,  94 
best  admixture  for  smelting,  97 


Gold,  best — 

amount  to  melt  in  one  opera- 
tion, 97 
California,  native,  average  fineness 

of,  92 

color  of,  83 
composition  of,  83,  84 
containing  osrn-iridium,   treatment 
of,     at    the     Mint 
in  St.  Petersburg, 
100 

treatment  of,   at  the 
United  States  Mint, 
99 
cradle   or  rocker,    illustrated    and 

described,  104-106 
ductility  and  malleability  of,  83 
exploitation,  necessity  of  an  "eye 

for  color"  for,  103 
extracted,  Pettenkofer's  statement 

regarding,  96,  97 
found  in  England,  89 
hardness  and  specific  gravity,  83 
in  Australia,  89 

marked  difference  in,  94 
in  fine  dissemination,  simplest  in- 
strument for  discovery  of,    103, 
104 
in    North    Carolina,    l)r.    Genth's 

description  of,  90-92 
in  rocks  of  various  ages,  90,  91 
in  Siberia,  89 
in  the  sands  of  rivers,  90 
Miller's  chlorine  refining  and  part- 
ing process  for,  94 
mines  of  South  America  and  Mex- 
ico, 86,  87 

native,  occurrence  of,  99 
necessary  precautions  in  the  treat- 
ment of,  109,  110 
occurrent   condition   and    form    in 

nature,  83 

of  Colorado,  color  of,  94 
of  the  world,  where  mostly  gath- 
ered, 89,  90 
ores,   discovery  and  proving,  103- 

106 
poorer,   Hungarian  process  of 

treatment,  108 
treatment  of,  107-109 
or  silver,  separating,  from  lead,  35 
poorer  ores  containing,  107-110 
production  of,  in  the  United  States, 

87,  88 

separating  silver  from,  122,  123 
specific  gravity  and  hardness,  83 


358 


INDEX. 


Gold- 
study  of  its  alloys  and  accompani- 
ments, 94-96 
sulphides.  88,  89 

United  States,  localities  of,  84-88' 
use  of  cast  iron  in  "parting,"  101- 

103 
of  platinum  vessels  in  parting, 

101-103 
Granza,  221 

Greisen,  per  cent,  assay  of,  177,  178 
Grindstones,  245 

home  product  and  import  of,  245 
principal  source  of,  in  the  United 

States,  245 
Groups  of  compounds,  42,  43 


HARDNESS,  a  characteristic  in  de- 
termination  of   many    mine- 
rals, 19,  20 
of    a   mineral,    standard    of 

comparison,  81,  82 
Heating  glassware,  69,  70 
Hematite,  characteristics  of,  139 

ores,  139,  142 

Hydraulic  mortar,  preparation  of,  333 
Hydrochloric    acid,    characteristics    of, 

and  tests  for,  49,  50 
symbol  and  atomic  weight,  49 
Hydrogen,  preparation  of,  44,  45 
symbol  and  atomic  weight,  44 
use  of,  in  reducing  finely  powdered 

iron  ore  to  iron,  44 
Hydrosulphide  of  ammonium,  process 

of  obtaining,  59 
symbol    and    atomic    weight, 

59 
Hydrosulphuric  acid  gas,  formation  of. 

51 

symbol  and  atomic  weight, 
51 


INCLINED  shafts,  masonry  for,  341 
Infusorial  earth,  244 

composition  of,  244 
localities  of,  in  the  Unitei 

States,  244 
uses  of,  244 
Ingress  and  egress  for  workmen,  illus 

trated  and  described,  316,  317 
Iodine  and  bromine,  symbols  and  atomi 

weights  of,  46 
uses  of,  46 
Iridium,  214-218 


riclium — 

and  phosphorus,  discovery  of  John 

Holland  in  regard  to,  217 
as  melted  by  the'older  chemists.  217 
color,  215 

commercial  value  of,  218 
derivation  of  its  name,  215 
geographical  distribution  of,  216 
gravity,  214 
hardness  of,  214 
in  the  United  States,  216 
lustre,  215 
malleability,  215 
melting  point  of,  217,  218 
occurrence  and  association,  214 
separation  of,  from  gold,  216,  217 
iridosmine,  214 

as  points  for  gold  pens,  21  7 
commercial  value  of,  218 
Iron,  137-174 

cast,  use  of,  in  parting  gold,  101- 

103 

chief  ores  of,  137-143 
dry  assay  of,  143,  144 
ductility  of,  137 
effect  of  phosphorus  on,  138 
effect  of  sulphur  on,  138 
electrical  conducting  power  of,  137 
heat  conducting  power  of,  137 
malleability  of,  137 
magnetic  ores  of,  137-143 
ore  at  the  Washington  mine,  near 

Marquette,  Michigan,  138 
deposits  of  the  United  States, 

exhaustion  of,  173,  174 
preparation  of,  for  the  assay, 

170-172 
to   ascertain   the   sulphur    in, 

156-158 
to  determine   the   amount   of 

manganese  in,  158-162 
ores,  associations  found  with,  138 
before  the  blowpipe,  143 
of  Great  Britain,  137 
pig,  increase  of  production  of,  in 

the  United  States,  173,  174 
polaric  ores,  where  found,  1 38 
pure,  specific  gravity  of,  137 
symbol  and  atomic  weight,  48 
tenacity  of,  137 

universally  present  in  nature,  137 
use  of,  for  volumetric  assays,  48 
volumetric  determination  of,   166- 

172 

wet  method  of  assay,  147-151 
Isinglass,  cleavage  of,  20 


INDEX. 


359 


TUDICIOUS    mining,    treatment    of 
J      the  ore  veins  in,  278 


T7ERMESITE,  228 
1\ 


T  ABORATORY,  selecting  a  location, 
Jj     63,  64 

Lead,  194-205 

action  of  water  on,  202,  203 
characteristics  of,  202,  203 
destroying  the  coining  qualities  of 

gold,  203 
ductility,  194 

electrical  conducting  power,  194 
fusibility,  194 
geological  horizons  and  occurrence, 

194-196 
gravity,  194 
hardness,  194 

heat  conducting  power,  1 94 
in  the  United  States,  194,  195 
malleability,  194 
ore,  by  the  wet  process,  197-199 
Mascazzinie's    method  of  as- 
saying, 204,  205 
working   on   the    large   scale, 

196,  199 

ores,  silver  contained  in,  114 
Park es's  process  for,  201,   202 
Pattinson's  process  for,  200 
quantitatively  determined,  204 
to  separate  silver  from,  123,  124 
separating  gold  and  silver  from,  35 
sulphate,  composition  of,  198 
tenacity  of,  194 

wet  assays  of,  and  methods  of  de- 
tection, 203,  204 

Lenses,  use  of,  for  blowpipe  practice,  33 
Levers  used  to  force  the  pipe  down  an 

artesian  well,  347 
Lime  carbonate,  cleavage  of,  20 
description  of,- 18 
to  distinguish  from  barytes,  22 
precipitation  of,  from  the  iron  fil- 
trate, 154,  155 
Lime-water,  symbol  and  atomic  weight, 

54 

Limonite,  where  found,  142 
Litharge,  symbol  and  atomic  weight,  54 

test  of,  54,  55 

Litmus  paper,  preparation  of,  63 
Lodes    and   veins,    how   prepared   and 
mined,  279-287 


Lodes — 

of  more  than  two  or  three  fathoms 
thickness,  method  of  working,  il- 
lustrated and  described,  285.  286 
Long  wall  system  of  mining,  illustrated 
and  described,  287-289 


MAGNESIA,  precipitation  of,   from 
the  iron  filtrate,  155 
Magnesium,  sulphate  of,  61 
Magnetism,  use  of,  in  determining  some 

minerals,  33 
Magnetite,  characteristics  of,  137-139 

geologic  position  of,  139 
Manganese,  206-209 

analyses  of,  by  the  wet  process,  209 
associations  of,  206,  207 
characteristic  color  of,  32 
characteristics  of,  206 
its  uses  in  the  arts  and  manufac- 
tures, 207-209 
oxide  of,    injurious   effects   of,    in 

building  stone,  208,  209 
on   a   borax   bead   under   the 

blowpipe,  31,  32 
to  determine  the  quantity  of,  in  an 

iron  ore,  158-162 
with  the  blowpipe,  206. 
Mascazzinie's  method  of  assaying  lead 

ore,  204,  205 
Masonry,  332-341 

and  timbering  of  mines,  317,  318 
durable,  requirements  of,  333 
for  shafts,  340,  341 

Masses  between  two  contiguous  drifts, 
to  gain  the,  illustrated  and  described, 
293,  294 
Mercurial  compounds,  characteristics  of, 

225-227 
Mercury,  218-227 

boiling  point,  218 
chemical  characteristics,  220,  221 
color,  218 
composition,  218 
ductility,  218 

geology  and  associations,  219,  220 
gravity,  218 
hardness,  218 

in  compounds,  Makins's  accurate 
method  for  determining,  226, 
227 

localities,  219 
occurrent  forms,  218 
ores  in  the  United  States  and  in 
Spain,  221 


360 


INDEX. 


Mercury  ores — 

treatment  of,  222-225 
to  separate  silver  from,  124,  125 
Metallic  oxides  completely  precipitated 
from  their  acid  solutions  by 
sulphuretted  hydrogen,  but 
not  from  their  alkaline  solu- 
tions, their  sulphurets  being 
soluble  in  alkaline  sulphur- 
ets, 43 

completely  precipitated  from 
their  solutions,  whether  acid, 
alkaline,  or  neutral,  by  sul- 
phuretted hydrogen,  their 
sulphurets  being  insoluble 
in  alkaline  hydrosulphurets, 
42,  43 

not  precipitated  by  sulphur- 
etted hydrogen,  but  precipi- 
tated as  oxides  by  hydrosul- 
phuret  of  ammonia,  42 
not  precipitated  from  their 
acid  solutions  by  sulphur- 
etted hydrogen,  but  com- 
pletely precipitated  by  hy- 
drosulphuret  of  ammonia  as 
sulphurets,  42 

not  precipitated  from  their 
solutions  by  sulphuretted 
hydrogen,  but  precipitated 
by  hydrosulphuret  of  am- 
monia only  under  certain 
circumstances,  as  salts,  and 
also  precipitated  by  alkaline 
carbonates,  42 

not  precipitated  from  their 
solutions  by  sulphuretted 
hydrogen,  hydrosulphuret 
of  ammonia,  or  alkaline  car- 
bonates, 42 
zinc,  manipulation  of,  under  the 

blowpipe,  30,  31 

Metal  or  mineral,  finding  specific  grav- 
ity of  a,   at  different  temperatures, 
25,  26 
Methylic  alcohol,   use  of,   for  burning 

and  for  blowpipe  purposes,  44 
Mica,  cleavage  of,  20 
Microcosmic  salt,  28,  29 

preparation  of,  63 

symbol  and  atomic  weight,  63 

Mineral  deposits  in  the  mines,  division 

of,  277 

making  a  distinction  between 
the  gangue  and  the  ore,  il- 
lustrated and  described,  273 


Vlineral  deposits — 

occurring  in  large  masses, 
preparation  and  working  of, 
292-296 

or  metal,  finding  specific  gravity  of 
a,  at  different  temperatures,  25, 
26 

Minerals,  cleavage  of,  20 
fracture  of,  20 
hardness    of,    characteristic    of    in 

determination  of,  1£,  20 
importance  of  color  in  determining 

their  nature,  20,  21 
requiring  other  than  blowpipe  treat- 
ment. 36 
scale  of  descent  of,  in  hardness,  81, 

82 

specific  gravity  an  important  char- 
acteristic of,  21,  22 
streak    an  important  characteristic 

of,  21 

useful,  economic  treatment  and  his- 
tory of,  81-251 
weighing  blocks  of,  without  scales, 

26 

Mine  crushed  in,  gaining  the  ore  in,  294 
floors  altogether  crumbling,  framing 
for,     illustrated      and     de- 
scribed, 322,  323 
loose  and  soft,  framing  for,  il- 
lustrated and  described,  322 
opening   or   exploring  of  a,   most 
important  rules  to  be  observed, 
271 

when  "exposed,"  277 
water,  construction  of  channels  for 
leading   off',   illustrated  and    de- 
scribed, 263 

exhausting  the,  two  ways  of,  281 
pumping,  264,  265 

Mines,  advantage  of  dry  walls  in,  338 
final  preparations  and  working  of, 

277,  278 

opening  of,  270-276 
robbing  of,  278 

timbering  necessary  for  working, 
illustrated  and  described,  330, 
331 

when  the  sides  are  firm  and  only 
the  roof  is  brittle,  timbering  for, 
illustrated  and  described,  323 
Mining  by  descending  steps,  284 
by  reversed  steps,  284 
carpentry,  318-324 
construction  and  machinery,   253- 
341 


INDEX. 


361 


Mining — 

downwards,    illustrated     and     de- 
scribed, 283,  284 
explanation  of  some  terms,  256 
judicious,  treatment  of  the  ore  vein 

in,  278,  279 
mineralogy,  necessary  information 

for  successful  study  of,  17 
preliminary      principles      and 

preparations,  17-29 
overhead,  illustrated  and  described, 

281-283 

preliminary   work    and    considera- 
tions, 257-270 
shaft  method  of,  265-270 
systematic,   requirements   of,    277, 

278 

well-conducted,  scientific,   system- 
atic, requirements  of,  275,  276 
when  expedition  is  required,  illus- 
trated and  described,  263,  264 
work  and  architecture,  253-341 
Mispickel,  deceptive  appearance  of,  113, 

114 
ore,  to  distinguish  from  silver  ore, 

114 
Molybdate  of  ammonium,  symbol  and 

atomic  weight,  59 
Molybdic    acid,    symbol     and     atomic 

weight,  53 
Monazite,  185,  186 
color,  247 
composition  of,  248 
hardness  of,  247 
lustre,  247 
gravity  of,  247 
under  the  blowpipe,  248 
Mortar,  preparation  of,  333 
Muffle,  charcoal,  for  small  assays,  35 
to  make  one  with  a  common  sheet- 
iron  stove,  34,  35 


NESTS,  cores,   or  pockets,  prepara- 
tion and  working  of,  295,  296 
Nests  of  ore  lying  separate  from  each 

other,  rule  for  opening,  275 
Niccolite,  characteristics  of,  132 
Nickel,  132-136 
alloys  of,  134 
before  the  blow-pipe,  132 
characteristics  of,  132 
consumption    of,     in    the    United 

States,  136 
ductility  and  tenacity  of,  132 


Nickel- 
glance,  symbol,  132 
lined  vessels,  advantages  of,  136 
malleability  of,  132 
ores,  132 

in  the  United  States,  135 
ore,  separation  of  its  constituents, 

134,  135 

prices  of,  135,  136 
pure,  Devill's  method  of  obtaining, 

135 

separation  from  cobalt,  136 
solubility  of,  132 
specific  gravity  of,  132 
Nitrate  of  barium,  symbol  and  atomic 

weight,  60 
test  of,  60 
of  potassium,  symbol  and  atomic 

weight,  55 

of  silver,  preparation  of,  in  crys- 
tals, 62 

proper  dilution  of,  61 
symbol  and  atomic  weight,  61 
Nitric  acid,  fuming,  use  and  preparation 

of,  78,  79 

symbol  and  atomic  weight,  50 
two  conditions  in  which  it  is 

employed,  50 

Nitro-prusside  of  sodium,  symbol  and 
atomic  weight,  59 


OCTAHEDRITE,  characteristics  of, 
248 

under  the  blowpipe,  248 
Oil  and  gas  wells,  350-352 
Opening  of  deposits  according   to  the 
positions  of  the  ore  veins,  272- 
274 

of  mines,  270-276 

Ore  gangways,  leveling  the  floor  of,  il- 
lustrated and  described,  269 
inclination     of,     consideration     in 
opening  a  lower  or  foot  drift,  il- 
lustrated and  described,  273 
in  the  mine,  assorting,  300 
Ore-mass  composed  of  hanging  and  ly- 
ing ore  veins,  working  the  drifts,  293 
Ore  samples   for  experiments,  caution 
to  be  observed  in  selecting,  145, 
146 
veins,  important  changes  of,   271, 

272 

vein,  treatment  in  judicious  mining, 
278,  279 


362 


INDEX. 


Ores,  cupellation  of,  120,  121 

iron,  containing   sulphides,  arsen- 
ides, or  selenium,  treatment  of, 
145 
Oreways,  recommendations   pertaining 

to,  264 

Osm-iridium,  211 
Oxalate  of  ammonium,  preparation  of, 

52 

test  of,  60 

symbol  and  atomic  weight,  60 
Oxalic  acid,  symbol  and  atomic  weight, 

52 

test  for,  52 
uses  of,  52 
Oxide  of  copper,   symbol  and  atomic 

weight,  55 
uses  of,  55 
of  manganese,  injurious  effects  of 

the,  in  building  stone,  208,  209 
of  zinc,  proportion  of  metallic  zinc 

in,  190 

pure,  characteristics  of,  189 
Oxygen,  processes  for  obtaining,  48 
symbol  and  atomic  weight,  48 

PALLADIUM,    extracted    from    ar- 
gentiferous gold,  100 
Parkes  process  for  lead,  201,  202 
Pattinson  process  for  lead,  200 
Permanganate   of    potassium,    coloring 

power  of,  57 

process  for  forming,  56,  57 
symbol  and  atomic  weight,  56 
use  of,  in  the  volumetric  anal- 
ysis of  iron,  57 

Peroxide  of  iron,  precipitation  of,   154 
Perpendicular    shafts,    construction    of 
walls   in,    illustrated   and  described, 
340,  341 

Phosphate     of    sodium,     symbol     and 

atomic  weight,  58 

test  of,  58 

Phosphorus,  extracting,  from  the  ses- 

quioxide  of  iron,  151 
extraction  of,  from  iron,  151 
Parry's   method   of   precipitating 

152,  153 

Piano  wire,  purity  of  iron  in,  48,  49 
Pig-iron,   increase  of  production  of,  in 

United  States,  173,  174 
Pillars,  taking  out  the,  290 
Pipes  used  in  sinking  artesian  wells,  34 
Platinum,  209-214 

color  and  streak,  209 


Platinum — 

crucibles,  requirements  of,  77 
foil,  use  of,  in  the  filtering  funnel, 

73,  74 

geology  and  occurrence,  210 
gravity,  209 
hardness,  209 
localities  of,  in  the  United  States, 

210,  211 
lustre,  209 

melting  point  of,  218 
native,  combinations  with,  209 
ore,  California,  analysis  of,  211 

table  of  the  analysis  of,  215 
production  of,  in  the  United  States, 

211 

wet  process  of  analysis,  211-214 
wire,    objection  to,   in  reducing  a 

metal  under  the  blowpipe,  33 
Poorer  ores  containing  gold,  107-110 
Post  and  stall  system,  preparatory  work 
for,  illustrated  and  de- 
scribed, 289,  290 
where  used,  289 
Potassa,  characteristics  and  tests  of,  53, 

54 

symbol  and  atomic  weight  of,  53 
Potassium,  chlorate  and  permanganate 

of,  56 
nitrate,  sulphate,  and  carbonate  of, 

55 

sulphocyanide  of,  57 
Practical  use  of  table  of  atomic  weights, 

39-42 
Precipitations,   to  calculate  the  weight 

of,  68 

Preparation  and  working  of  mineral  de- 
posits   that    occur    in   large 
masses,  292-296 
of    nests,    cores,    or    pockets, 

295,  296 
of  stratified  deposits  and  beds, 

287-292 
Preparatory  practice  with  the  blowpipe, 

29-35 
Protosulphide   of  nickel,    precipitation 

of,  134 

Protoxide  of  nickel,  care  required    in 
precipitating  by  potassa,  134 
precipitation  of,  133 
Pumice  stone,  243,  244 
color  of,  243 
gravity,  243 

imported,  composition  of,  243 

only  utilized  deposit  of,  in  the 

United  States,  243,  244 


INDEX. 


363 


Pumice  stone — 

value  of  importations,  243 
Pumping,  mine,  264,  2(55 

or    ventilating   division    of    shaft, 

necessary  platforms  in,  328 
Pyrargyrite,  characteristics  of,  116 


QUARRIES,  difficult  of  access,  tun- 
nelling for,  298 
with  very  thick  covering,  tunnelling 

for,  298 

Quarrying  for  large  stones,  etc.,  297 
materials  gained  in  open,  297 
solid  rock,  297 
when  the  mass  is  loose,  297 
Quartz,  analysis  of,  18 


RAIN  water,  pure,  weight  of,  23 
Reagents  and  glassware,  how  to 

use,  68-71 
the,  43-63 

Reamer,  use  of,  in  boring  a  well,  346 
Red  antimony,  228 
Red  hematite,  characteristics  of,  139 

not  attractable  by  the  magnet, 

140 

ore,  condemnation  of,  from  de- 
ceptive appearances,  19 
limit  of  per  cent,  of  iron 

in,  140 
variations  in  its  characteristics, 

139,  140 

litmus  paper,  preparation  of,  63 
Renewing  timber,  331,  332 
Robbing  of  mines,  278 
Rock,  barren,   met  in  a  deposit,  treat- 
ment of,  illustrated  and  described,  287 
Rock-salt  works,  mining  in,  illustrated 

and  described,  294,  295 
Rods  used  in  boring  artesian  wells,  346 
Roof,  supporting  the,  290 

weak,  sinking  side  pits  and  timber- 
ing for,  illustrated  and  described, 
269 

Roofs  or  walls,  supporting,  291 
Roots'  blower,  200 
Rotten  stone,  244 
Ruby  silver,  characteristics  of,  116 
Rutile,  164 


s 


ALT,  microcosmic,  28,  29 

mines,  forming  posts  and  caps  in,  il- 
lustrated and  described,  321,  322 


Salt— 

of  lead  paper,  uses  of,  63 
Sand  bath,  64 

pump,  description  and  use  of,   in 

boring  artesian  wells,  346 
Scale  of  descent  of  minerals  compared 

with  the  diamond,  81,  82 
Scales  for  specific  gravity,  36 
Scorification  of  mixed  ores,  118-120 
Semicircular  arch,   illustrated  and   de- 
scribed, 336 
Sesquioxide   of    nickel,    formation    of, 

133 

Shaft,   direction  or  inclination  of  a,  to 
be  exactly  and  continuously  pre- 
served, 267 
framing,  section  of,  illustrated  and 

described,  266,  267 
in  rock  or  soil,  opening  of  a,  illus- 
trated and  described^  268,  269 
method  of  mining,  265-270 
permanent  timbering  of,  illustrated 

and  described,  325,  326 
straight  and  vertical,  used   as  ex- 
perimental or  permanent,  illus- 
trated and  described,  267 
sunk  on  a  vertical  line,  illustrated 

and  described,  267,  268 
timbering,  lining  of,  illustrated  and 

described,  326,  327 
when   all    the   sides   do  not   need 
timbering,    illustrated    and    de- 
scribed, 327 
Shafts,  buckets  in,  305 

in  swamp  lands,  masonry  for,  341 
leading  the  water  from,  illustrated 

and  described,  270 
masonry  for,  340,  341 
more  than   20  fathoms  deep,   ma- 
chines   for,    illustrated    and    de- 
scribed, 305,  306 

perpendicular,  having  several  divi- 
sions,  timbering  for,   illustrated 
and  described,  327,  328     • 
pile  driving  in,  illustrated  and  de- 
scribed, 327 
(slopes),   inclined,   timbering    for, 

329,  330 

timbering  of,  324-329 
when  rock  is  to  be  drilled,  265 
working  downwards,  265 

from  below  upwards,  265 
Shutes  or  transporting  shafts,  330 
inclination  of,  302,  303 
in  the  lower  plane,  illustrated  and 
described,  303 


364 


INDEX. 


Siderite,  142 
Silver,  111-125 

antimonial,  description  of,  114,  115 
assay  by  the  dry  way,  116 
bismuth,  description  of,  115 
caution  against  precipitating,  with 
chlorides  of  potassium,  sodium, 
and  ammonium,  123 
color  of,  111 
composition  of,  111,  112 
ductility  of,  111 
found  in  other  ores,  1 1  4 
from  sulphurets,  to  separate,  125 
gravity  of,  lit 
hardness  of,  111 
localities,  geologv,  and  associations, 

112-123 
Makins's   process   of  assaying  by 

cupellation,  116,  117 
mines  in  the  United  States,  113,  114 

foreign,  112,  113 

native,  table  of  specific  gravities  of, 
at  different  temperatures  of  the 
water,  25,  26 
nitrate  of,  61 
occurrent  form   or   appearance   in 

nature,  111 
ore,  first  step  required  in  the  assay 

of,  117,  118 

ores,  general  resemblances  of,  114 
or  gold,  separating  from  lead,  35 
ruby,  characteristics  of,  116 
separating,  from  copper,  122 

from  gold,  122,  123 
shop  sweepings,  assay  of,  118,  120 
to  separate,  from  cadmium  and  bis- 
muth compounds,  124 
from  lead,  123,  124 
from  mercury,  124 
wet  process   or   humid    assay   of, 

122-124 

Sinking  artesian  wells,  343-350 
Slope,  advantage  of,  over  the  perpen- 
dicular shaft,  266 

in   coal   beds,   illustrated   and  de- 
scribed, 268 
sinking  a,  illustrated  and  described, 

261 

Slopes,  timbering  the  partitions,  illus- 
trated and  described,  329, 
330 

to    support    the    overhanging 
rock,     illustrated     and 
described,  329 
the   roof,   illustrated  and 
described,  329 


Sluice,  construction  of,  259 

in  a  gallery,  construction  of,  illus- 
trated and  described,  339 
Smaltine,  238 
Smithsonite,  185,  186 
Soda,  symbol  and  atomic  weight,  54 
Sodium,  chloride  and  sulphuret  of,  57 
disulphate,  use  and  preparation  of, 

78,  79 

nitro-prusside  of,  59 
sulphite,     carbonate,      phosphate, 

acetate,  succinate,  58 
Solid  rock,  quarrying,  297,  298 
Spathic  ore,  characteristics  of,  142 

Kipp's  apparatus  to  determine 
the  amount  of  iron  carbonate 
in,  illustrated  and  described, 
162,  163 

where  found,  142,  143 
Specific  gravity,  an  important  charac- 
teristic in  mineralogy,  21,  22 
.     scales  for,  36 

simplest  way  of  determining, 

21,  26 

use  of  distilled  water  in  making 
accurate  determination  of, 
24,  25 

Specular  ore,  appearance  of,  139 
Speiss,  composition  of,  153 
Sphalerite,  183 
Spiegel  iron,  208 

Spiral  auger,  operating  the,  346,  347 
use  of,  in  boring  a  well,  346 
Splitting  rock  with  wooden  pins,  297 
Spontaneous  combustion  in  coal  mines, 
generally  supposed 
cause  of,  291 
most  effective  means 
of  prevention,  291, 
292 

Spring  catch,  use  of,  348 
Stannite,  176 

geology  of,  180 
Staurolite,  177 
Steam-engine,  illustrated  and  described, 

310-314 

Stephanite,  characteristics  of,  115 
Stibnite,  228 

before  the  blowpipe,  228 

color  and  streak,  228 

deposits  of,  in  the  United  States, 

228,  229 

extraction  of,  230 
foreign  localities  of,  229 
hardness,  228 
lustre,  227 


INDEX. 


365 


Stibnite— 

occurrence  of,  228 
Stones,  proper  join i nor  of,  333 
Stratified  deposits  and  beds,  preparation 

and  working  of,  287-292 
Streak  an  important  characteristic  of  a 

mineral,   21 
Stream  tin,  175 
(Stripping  or  removing  surface  for  veins, 

296 

Succinate,  neutral,  of  ammonium,  pre- 
paration of,  60 
symbol  and  atomic  weight, 

60 
of    sodium,     symbol    and    atomic 

weight,  58 
test  of,  59 
Succinic     acid,     symbol     and     atomic 

weight,  52 
use  and  test  of,  52 
Sulphate  of  magnesium,  preparation  of, 

61 

symbol    and    atomic   weight, 
"  61 
of  potassium,  symbol  and  atomic 

weight,  55 
test  of,  55 
Sulphite  of  podium,  symbol  and  atomic 

weight,  58 
test  of,  58 
Sulphocyanide    of    potassium,    symbol 

and  atomic  weight,  57 
Sulphuret  of  sodium,  process  of  making 

a  solution,  57 
symbol    and    atomic    weight, 

57 

use  of,  57 
Sulphurets,    to    separate    silver    from, 

125 
Sulphuric    acid,  characteristics   of  and 

tests  for,  50,  51 
precaution  in  using,  50 
symbol    and    atomic    weight, 

50 
Sulphurous  acid  or  anhydride,  symbol 

and  atomic  weight  of,  53 
preparation  of,  53 
Sulphur,    to  ascertain    the,  in   an  iron 

ore,  156-158 
Sumpt,  proper  location  for,  266 

(sumpf),  location  of,  264 
Surface  or  day  working,  296-300 

where  applicable,  296 
working,  divisions  of  work,  291 
Systematic    mining,    requirements    of, 
277,  278 


TABLE  of  atomic  weights,  practical 
use  of,  39-42 

of  chemical  symbols,  37,  38 
of  combining  weights  of  elementary 

bodies,  38,  39 

of  specific  gravity  of  native  silver 
at  different  temperatures  of  the 
water,  25,  26 

of  the  analysis  of  the  ore  of  plati- 
num, 215 
Tartaric  acid  solution,  treatment  of,  52, 

53 

symbol  and  atomic  weight,  52 
Terrero,  221 
Test  iron,  preparation  of,  for  volumetric 

determination,  167-170 
Tierras,  221 
Timbering  and  masonry  of  mines,  317, 

318 
necessary   for  working    in   mines, 

330,  331 

of  inclined  shafts,  329,  330 
of  shafts,  324-329 

commencement  of,  illustrated 

and  described,  324,  325 
renewing,  331,  332 
to  secure  greater  durability,   illus- 
trated and  described,  319-321 
Tin,  174-183 

before  the  blowpipe,  179,  180 
California,  assay  of,  178 
estimating  the  amount  of,  in  any 

compound,  182 
extraction  of,  180-182 
in  the  United  States,  176 
localities  and  geology,  176 
mineralogical   appearance  of,   178, 

179 

occurrent  form,  175,  176 
practice  with,  under  the  blowpipe, 

31 

specific  gravity  of,  174 
stone,  178 
stream,  175 

symbol  and  atomic  weight,  49,  175 
uses  of,  49 
Titanic  acid,  detection  of,  164,  165 

where  found,  1 64 
iron  ore,  to  extract  the  titanic  acid 

from,  165,  166 

Tramway,  joists  for,  illustrated  and  de- 
scribed, 340 

Transportation,  300-317 
general  rules  for,  301 
on   steep   inclines,  illustrated   and 
described,  314-317 


366 


INDEX. 


Transportation — 

through  galleries  and  drifts  having 
an  inclination  of  more  than  10° 
and  less  than  30°,  illustrated  and 
described,  301,  302 
through  shafts,  illustrated  and  de- 
scribed, 302 

through  shutes,  302,  303 
Transporting  division  of  shaft,  caution 

in  regard  to  buckets,  328 
gallery,  complete  timbering  of,  il- 
lustrated and  described,  328,  329 
shafts,  wooden  partition  and  tloor 
in,  illustrated  and  described,  330 
Trial  shafts  or  excavations,  257 
Tripoli,  244 
Tunnel,   arched,  construction   of,  337, 

338 
Tunnelling  for  quarries  with  very  thick 

covering  or  difficult  of  access,  298 
Turbine  blades,  form  and  curvature  of, 

illustrated  and  described,  309 
wheels,  use  of,  309 


VALENTINITE,  228 
Valve  sockets,  use  of,  347 
Vaults,  danger  of  crushing  in  working 

the  drifts,  293 

Vein  dividing  into  several  branches,  272 
having  a  selvage  or  partition  rock, 

treatment  of  a,  284 
not  over  twelve  feet  thick  and  to 
be  mined  overhead,  working  of 
a,  illustrated  and  described,  279, 
280 
or  lode,  not  uniformly  rich,  method 

of  working,  285 
thin  or  pinched,  272 
working  of  a,  in  case  of  a  fault, 

272,  273 
Veins   and   lodes,    how   prepared    and 

mined,  279-287 
ore,    important    changes   of,    271, 

272 
Volumetric  determination  of  iron,  166- 

172 

preparation  for,  167 
by   potassium   permanga- 
nate, 166 


WALL,  to  give  a  firm  position  to  a, 
illustrated  and  described,  334 
Walls,  dry,  advantage  of,  in  mines,  338 
for  filled-in  spaces,  arches  for,  341 


Walls— 

or  roofs,  supporting,  291 
preparations  for  beginning,  334 
Washboard  for  buddling,  299 
Water  at  the  side  of  a  shaft,  manner 

of  draining,  341 
collecting  of  pure,  70,  71 
for  finest  analyses,  43,  44 
formula  of,  43 
of     crystallization,     intumescence 

caused  by  escape  of,  31 
pure,  use  of,  in  determining  a  spe- 
cific gravity,  24,  25 
Weighing   blocks    of  minerals  without 

scales,  26 
Wells,  machinery  for  digging,  350 

oil  and  gas,  350-352 
Wet  assay  of  iron,   Wohler's   method 

of,*  150,  151 

method  of  assay  for  iron,  147 
Wheel  and  shaft,  position  of,  illustrated 

and  described,  309,  310 
Whim,  water,  illustrated  and  described, 

307-309 
Willemite,  186 
Windlass,  the,  illustrated  and  described, 

303-306 
Wohler's  method  of  wet  assay  for  iron, 

150,  151 
Wood  tin,  178 

Workmen,    ingress  or  egress  of,   illus- 
trated and  described,  316,  317 
"  Wrench  bar,"  use  of,  in  well  digging, 
348 


,  characteristics  of,  248 


F7AFFRE,  238 
/J  Zinc,  183-193 

carbonate  of,  185 

of,  under  the  blowpipe,  186 

color  of,  183 

distillation  of,  49 

distilling,  187-189 

ductility  of,  183 

granulation  of,  44 

gravity  of,  183 

impurities,  184 

in  the  United  States,  184 

localities,  foreign,  184 

metallic,  hardness  of,  183 

melting  point,  184 

occurrent  form  of,  1 83 


INDEX. 


367 


Zinc- 
oxide,    Belgian    distilling   process, 

189 

pui-e,  characteristics  of,  189 
Silesian  distilling  process,  189 
proportion  of  metallic,  in  the  oxide 

of,  190 

pure  metallic,  obtaining  by  the  wet 
process,  190-193 


Zinc- 
purifying  of,  44,  45 
silicate  of,  appearance  of,  185 
sulphide,  characteristics  of,  185 

where  found,  184 
symbol  and  atomic  weight,  49 
under  the  blowpipe,  185,  186 
uses  of,  49 


(I? 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 
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